I'll answer here, cause I was already here. :) I'm not really aware of the specifics you mention, even if my name might be attached to the action. There was no new amnesty this year, as I was on vacation during the period we normally do those — and still am!
So feel free to use your best judgment. That said, do please consider that whatever offences were caused were done a loooooong time ago, so there might be cause to give a new, direct warning to the user and hope that the bad behaviour is in their past.
I understand your point here that the Wiki is unavailable for adoption. Unfortunately, since the administrators have become inactive three years ago, and the FANDOM staff is not taking a look at its contents, garbage pages (like this), which serve to inflate or manipulate the wiki's article count, have been created, such as fake rating systems and pages which are irrelevant to the goals of the wiki.
I think you might have misinterpreted a few things.
First, users on Fandom need not give notice that they've left, or ask permission to return. People come and go all the time, without warning. "How is DeepThink back?" I dunno; they just are.
Second, DeepThink's profile page wasn't deleted. It simply was never created. Moreover, the existence of a profile page has no bearing on a user's account. Every user has hundreds of thousands of wikis where they have no profile page. But clearly their accounts still function.
Remember: for any page — be it an article or a user page — a red-link simply means the page doesn't currently exist. That could mean it was deleted, but it much more commonly means that it was never created in the first place.
Finally, I'm not sure where you're getting the notion that DeepThinks was gone for two years. There's no evidence to support that assumption. But they weren't gone that long, since the wiki only dates to about September 2019.
So, as I said in the adoption request closure, you now have to go through them. I realise this might frustrate you, but in some ways it's a good thing. I was unlikely to approve the adoption, because the arrival of the new episode on the 7th did effectively nothing to improve the wiki's viewing statistics. It's still essentially a dead wiki. Now, though, you have another active editor on the wiki — and the founder, to boot! — meaning, maybe, together, you can create a more active community.
The wiki is definitely better off than when you first submitted an adoption request!