I don't see what useful information the motte and bailey lingo actually conveys that equivocation and deception and bait-and-switch didn't. And I distrust any turn of phrase popularized in the LessWrong-o-sphere. If they like it, what bad mental habits does it appeal to?

The original coiner appears to be in with the brain-freezing crowd. He's written about the game theory of "braving the woke mob" for a Tory rag.