I believe Roger and Whitebeard are rivals but not enemies.
Of course we want to see those beasts fighting, but why would they? Even a friendly match right now would seem kinda out of place. They might talk about the God Valley incident and Roger will explain that he had a problem with Rocks himself, not with his entire crew.
My prediction is this: Roger will flat out invite Oden to join him (Luffy style) and explain to him his plans for his final voyage. Maybe Roger will even threaten to fight Whitebeard to win Oden, but Whitebeard will explain that Oden was never really his subordinate.
He’s free to do what he wants. Oden will be interested but will refuse and say he will remain with Whitebeard out of loyalty.
Whitebeard will say he has no interest in making a similar voyage and will encourage Oden to join Roger to finally fullfil his wanderlust because this will be his only chance.
Oden will agree to join Roger. We’ll see a farewell scene with tears all around. Whitebeard’s crew will agree to take Toki and the kids back to Wano.
Now even if a friendly fight does happen, I don’t think we’ll see it. Oda usually skips fights that don’t include the Straw Hats or their temporary allies within an arc. I would love to see a fight like that though. I just don’t think we will.