Thats the main reason WHY a rage quit is the most likely option here...Just 2 weeks before releasing the next update and just a couple of days after revealing the releasedate? I doubt it.
Or more like "he snapped and throw everything in the bin"
Did you ever in your life code something? No?
I tell you how it can go... you code and code, everythings seem fine... you are reaching the "end" of the project and you stumble over an error... than another one... and you realise "oh fuck, the error chain is actually beginning very early and i cant figure out where" And thats it... he huge fucking rat-tail is coming. Cause your coding was sloppy in the beginning, and those add up, in a huge fucking way unsolveable.
TLG had made himself a deadline for the release... and most likely stumbled over those errors. And if you know just a little bit about coding and take a closer look to the game while playing... you will notice a TON of little errors and bugs. Choices made were ignored, variables doesnt function and so on and on... many times girls act towards the MC as something happened between them, even if it wasnt the case. And those werent a few, you could see many those little errors.
Now TLG was reaching the end of the first "season" how he called it... branching must be solved, and so on... but if you already piled up those little errors, they will become a HUGE barrier for the end.
And than it goes like this for example... you faceplam yourself, get annoyed and throw everything in the bin cause you cant manage all that anymore.
On top of that, TLG was mentally unstable, he told this in discord a while ago and made a patreon post about it too... if your mental health isnt the best, and you face a problem you cant solve as you whish, most people in this state just "quit" and vanish.
Iam one of those who did just that more than once, and i know a bunch of others too (met them through therapy)
And TLG is one of those people i assume to more likely runaway from the problem instead of solving it. No offense, as i said, iam like that myself.
So even IF he made a good amount of money with the game (and he did) its very clear, he couldnt handled the pressure and stress anymore, and his project was not well coded too, which causes big problems in the progress.
His initial plan was to release the first half of episode 6 in august, and he couldnt make it... he said back then that he would release the whole episode as one in november... just 2 weeks before the announced release he vanished and everything was deleted in an instant.
There is no other explanation possible, he only can do it himself like that. He quit discord too, no messages, no nothing.
Dead people dont delete a patreon page, other issues would be known by now... copyright issues? solveable and again... it would be know by somebody already.
No TLG just vanished from the internet, which is pretty easy to do, he simply pulled the plug, closed his accounts too, left discord, and thats it... he is gone. Thats it, not really a big mistery if you know some people with depression for example.
Its a very common reaction for people who are mentally not that healthy to just go in isolation and quit a project in an instant.
Its nothing that dramatic either. Has nothing to do with suicide or something like that. He most likely just snapped at the project cause he couldnt do it like he wanted and couldnt handle some problems, problems which were obvious if you take a closer look to the game as i said. There are even bugs in the very first chapter that are still not fixed, cause he cant fix them.
He couldnt code it like it had to be done... snapped, and quit... thats it. Every other explanation doesnt make any sense at all, cause there is no other reason why he left the discord and deleted the patreon page at the exact same time. He did it himself and didnt wanted to face a reaction to it either.