Itauma assuming he's as good as the hype suggests and Kabayel is a dark horse aswell. I could see Kabayel beating the brakes off Dubois quite honestly.
I don't think there will any "ruling" perse. Probably back to a pre-Klitschko scattered belts kinda era. Kabayel might do pretty well, but he will probably be frozen out by the Brits as much as humanly possible. I can't see one of them really dominate the others, so they will probably play HW musical chairs with 2 of the belts with one maybe held by Parker or held hostage by one of the Americans again.
Defo possible but I think Kabayel is pretty hittable and can get hurt. Would be a great fight. Dubois would have to get him out of there very early though.
As who will rule the HW division in 3 years time if Uysk has a couple more fights left if I had to guess? A good chance Dubois will be in his prime still as he'll only be 30. Obviously you have potential prospects who in my view are still hype jobs until proven so. Such as Itauma, Torrez, Teremoana Teremoana, the Pero brothers and Jalolov. I like the point @Robney made with no clear best fighter possibly then.
Kabayel or Itauma. Dubois is gatekeeper material. I've seen the super heavyweight amateurs and the new prospects like Mullojonov, they are more skilled and smaller than the last generation. Dubois is not lasting in the next era
this may well be the answer. Although if Ituama really is as good as the hype says, he may knock over the division and collect all the belts. It could end up being a Mike Tyson repeat for a while.
It depends how long Usyk goes on for and I doubt anyone will dominate things like he has. Parker and Dubois are the obvious choices if Usyk retires soon. With Kabayel potentially also in the picture. If Usyk hangs around for a while, Opetaia is a possibility and Itauma, at only 20, might eventually take the mantle.