This is a great idea. While devs could circumvent this by just pushing small, meaningless updates to refresh the timer, truly abandoned projects would still be flagged.
I assume that it's his relation to endorsing X again after he left it's(bsky) board after bsky refused to enter federation territory and then proceeded to add moderation tools to the platform (an action he was strictly against as he wanted it to be completely freedom of ideas).
TBH I agree with a lot of his mentality on it(that it should be further into the federation territory), while I do think some moderation tools are needed, but I think he loses all credit to his claims by endorsing X as the platform that is capable of doing what he wants.