Anything they "maintainer of last resort" would actually be forks, or collectively a distribution. We already have hundreds of distributions acting as maintainer of last resort many times over, only with actual developers and not presuming to make themselves the new upstream for anyone else.

Microsoft controls NPM and GitHub. I would not put it past them to truly take over a project if they gauged it in their best interest (though it would be a massive violation of trust, so I'd imagine they'd tread carefully before going there).

If it's sent to Akrites, they can even pretend it's done responsibly – even though only megacorps get a seat around that table.