not by much, usually I review the data models to absorb their design and translate into lessons

No. It's more like a writer describing their creative process. Knowing how someone else gathers ideas or structures text may help you improve your own writing, but that is still a very small part of publishing an original work.

If they can extract the game engine code into a reusable framework, yes.

No game created from it could ever be legally released though.

If it's a closed source release, how could anyone prove which code/framework they reused ?

I'd imagine a complex game engine has some bugs or weird behaviours in specific conditions. If it can be proven that the closed source game has a lot of the same bugs/behaviours, that is likely enough to win a lawsuit.

>Reverse engineers have entered the chat room.

Finding this would be pretty trivial depending on how much was stolen. And proving this would be more of a matter for Rockstar lawyers

Decompile it and see things work exactly the way the original game does, bugs and all

Can’t you decompile it?