Fads come and go. At least, Microsoft didn't jump into the crypto wagon. The space theme looks overblown and childish. What has that to do with code or AI?
It's likely one key reason for Microsoft buying Github was to have a very easy way to train their AIs on real code.
Move open source code to other venues would only make it a bit more expensive to do the same. And they could buy that other venues, too.
Maybe it's time the FSF or the EFF or the like creates a Github alternative.