Will any of the 2018 one-term wonder Democrats ever return to congress?
Of the seats Democrats lost in 2020, they only got one back in 2022 (NM-02) and that was only because of redistricting. It's also the only one of these districts that Democrats drew at all, whereas Republicans drew, or otherwise had power in the redistricting process of, every flipped seat that was in a red state. Only one former congressman ran at all, Max Rose, and he got screwed over by the NY Court of Appeals and it's not clear he would have won anyway given that Zeldin won the gerrymandered NY-11.
As of 2024, Harley Rouda is making a comeback but it's not clear whether or not he'll win.
I think Harley Rouda has an excellent chance at winning, and he's the first one who came to mind when I saw your question.