They are just setting the stage for themselves to not run him again. People expect a president to run for both terms and its pretty clear that Biden is far too much a liability to even have a chance of them letting him. But to outright say that would be admitting the haters were right about him all along.

This is just standard Leftist tactics. Throw a few softballs to pretend they aren't completely compromised when the tide starts to turn on them, toss out a scapegoat figurehead to act like they will totally hold themselves accountable and then play it slightly quieter for a bit.