I think that Obama hates critical theory identity politics. The nature of politics being politics, it's true that it may not be politically advantageous for Democrats in power to speak about it that directly (when they need those votes to win, at least for now). On the other hand, there are plenty of Democrat and left-leaning people out there who are certainly opposed to critical theory, and their participation would be decisive in the coming years.

The problem with Trump and his supporters is that they want to 'own' the anti-critical theory issue all to themselves, and worse, to use it to hurt Democrats. With Trump's divisiveness out of the picture, a cross-party alliance against critical theory can be more easily built. Without Trump being there, anti-critical theory liberals will be more likely to speak up, even if Biden and Harris themselves do nothing. It's our only hope to change things, I think.