If Usyk decides to bow out after this one, Dubois vs Parker for one of the belts. If Usyk continues to hold all the belts and have rematches, I don't think Dubois will fight Itauma, as it's far too early for Itauma. Dubois won't want to go back to the fringe world level, which is where Itauma will be if he beats Whyte. Probably a keep busy fight to get a win, maybe someone like Wallin?
Tasting canvas again and again and again as he transitions from suspect-chinned titlist to confirmed glass-jawed trialhorse. He's packing guys. Saturday will show this clearly: https://www.boxingforum24.com/threads/daniel-dubois-has-a-glass-jaw.696063/
Dubois is young enough to come again if he loses, whereas Usyk is on his swansong. Besides Usyk there's not many, if any that can beat Dubois at the moment so it's not the end of the world if he were to lose.
In fairness, with how little championship quality there is out there right now... Worse things could happen. And I'd still like to see him fight Parker - whether he will or not is another question (regardless of the outcome with Usyk). Ultimately, he'll be back before too long - he's shown before he can lose and rebuild confidence... And that's a strength not everyone has - not to mention he's got the ability to get back up there, one way or another.