Update 4: Thanks to Lance M., there is now a petition on change.org that you might consider signing in order to give visibility to the matter and perhaps motivate Take-Two to reconsider their scorched-earth approach. If you have any friends who are into VR or mods in general, tell them too!

Update 3: I have removed from the Patreon everything that can be even remotely associated with IP by Take-Two, Rockstar and 2K.
Patreon doesn't provide any functionality to archive, backup or hide posts, so I had to implement a workaround (ain't that always the case?): you will see that my page now has a new tier called "Archived posts". That tier is accessible only to me, and I'm using it to preserve all of the old information, tutorials, your valuable comments and guides. Unless Patreon arbitrarily decides to pull the plug, I'm not voluntarily destroying forever that wealth of materials that YOUR monetary support has paid for.
I will now contact Patreon directly and ask for the page to be restored to normal status, as this is how it appears to me at the moment:

I will also create a new post explaining what I believe we should do as a community; attached to that new post you will find a crippled release that drops all support for the games that Take-Two, Rockstar Games and 2K Games don't want their paying customers to be able to play in VR.

Update 2: There is not much time left until the DMCA 48-hour deadline expires.
One full day has gone by already since I asked for a communication channel with Take-Two and a Patreon rep replied to me: "I will reach out to Take-Two directly and see what contact method they would be willing to provide, and I will reply as soon as I have received their answer." After that, I received no further messages from Patreon, and apparently nobody has been able to get in touch with any representative from Take-Two.
To the best of my knowledge, Take-Two received requests for comment and/or for clarifications from The Verge, Kotaku, UploadVR, Rock Paper Shotgun, and of course from myself via Patreon, and they didn't bother to respond to anybody.
Additionally, Patreon failed to comply with my request to receive a copy of the original DMCA notice that Take-Two sent to them (as I never received any direct communication from Take-Two, in writing or any other forms). One almost gets the feeling that Patreon cares more about steering clear of any risks of being held liable than they care about protecting their creators from arbitrary (ab)use of the DMCA nuke.
So, since Patreon is threatening to suspend my account although by their own admission they don't even know what "the specific URLs at issue" are, for the moment I have no other option than to remove EVERYTHING even remotely related to Rockstar and 2K games. This is exclusively meant to minimize disruption to my Patrons who otherwise might see the provider denying access to every part of the service they pledged for, even those portions having nothing to do with the current action.
I have already begun the process and it should be complete in the next 16 hours or so. All posts pertaining to the games involved will be archived and will no longer be accessible, and my R.E.A.L. framework will be updated to a new version that completely removes support for Rockstar and 2K games. Unless/until an agreement is reached with Take-Two, I will also be in the position where I won't be able to respond to any support requests regarding those games, at least as long as the matter is being disputed.
Note that none of the above might be construed to imply that I admit any wrongdoing or believe that Take-Two's DMCA notice has any legal merit. On the contrary, it is my belief that their action is wrongful and unmotivated, and that they are willfully making it much worse by their refusal to communicate, and I reserve the right to take legal action against any and all of the parties involved.
Dear friends, please forgive me as for obvious reasons I'm currently unable to respond to your requests for tech support. During the past year I never missed one day of replying wherever help was needed, but now that the community is under attack there are other priorities. I'm still trying to read all your messages and comments, and I am moved by the way you guys are coming together against this soulless, voiceless corporate maneuver, but I don't have enough time to reply to each one of you!

Update 1: You're unfailingly awesome, both in good and difficult times!! Thank you so much to everybody who reacted to this, with words of encouragement, words of warning, legal or semi-legal advice... even by increasing your pledge! Honestly, I'm overwhelmed by your reaction and I love you all <3
Sorry that right now I cannot personally reply to all of you!
As promised, I'm keeping you updated though: no word from Take-Two for now, but Patreon has offered to try and establish a direct channel. I'm grateful for that and I hope that the effort will succeed and lead to a positive resolution, because I'm firmly convinced that what we're doing cannot be hurting Take-Two's bottom line in any way.

Original text:

I just received a DMCA takedown notice from Take-Two Interactive Software, Inc., parent company of Rockstar Games, Inc. and 2K Games, Inc., in relation to Grand Theft Auto, Red Dead Redemption 2, and Mafia Definitive Edition.

They are demanding that I remove all their copyrighted works from my Patreon page.

I immediately asked for clarifications, since it is my belief that I'm not hosting any such materials. As you all know, I do create and distribute original modifications for those games, i.e., original pieces of software of my own creation that allow users to experience those games in a different and hopefully more intense and profound way. However, none of my modifications are built using software belonging to Take-Two Interactive Software, Inc, and the modifications are not intended to replace their games, nor are they a means of exploiting Take-Two Interactive Software, Inc's proprietary IP or assets. All of my modifications require that users buy and own the games before they can add my modifications.

I have no experience with DMCA notices, so I don't know whether it will actually be possible to obtain such clarifications and to understand what materials specifically Take-Two believe to be in violation of their rights. To prevent unrelated discussions, please note that this was filed as a copyright issue and not a licensing issue, so the motivation for the request does not appear to be related to the fact that there is money involved.

I'm publishing this post first and foremost to keep you appraised of the situation, and secondarily to ask you for help in case any of you knows what channels I might use in order to get a better understanding of what Take-Two wants.

As I publicly stated many times, I honor and respect copyright and my intention has always been to allow gamers to experience the wonderful worlds created by Rockstar and 2K (among other companies) in Virtual Reality, which only translates to more customer satisfaction and more copies sold for them. I don't sell or host anything exploiting or repurposing their original IP and assets and my mods only work if the user already owns a legal copy of their original games.

That said, if I get no clarifications from them allowing me to determine what they want removed, I will of course be forced to take down anything even remotely related to any product made or distributed by Take-Two Interactive Software, Inc., Rockstar Games, Inc. and 2K Games, Inc.

Again, as I always said, if left in the dark I can only err on the side of caution, and I will not risk other games being involved in the purge in case Patreon elects to shut down my page. That means that all posts, images, guides, recommendations, tutorials and above all my VR mods for GTA V, Red Dead Redemption 2, Mafia: Definitive Edition, Mafia II: Definitive Edition, Mafia III: Definitive Edition will be taken down and will no longer be accessible to download.

I refuse to believe that is what Take-Two Interactive Software, Inc. wants, because that would be an extremely anti-customer and anti-gamer move on their part. But I am not getting in a legal battle with them. If what they want is to assert their corporate dominance with gamers' interests as collateral damage, I have no power to stop them.