Kownacki looks tough and has an awkward style, but he's very poor defensively. I can see Whyte jabbing his head off at range for a few rounds before lowering the boom. If Kownacki can take it then we might see him lasting into the later stages of the fight, but I can see facial damage being a major problem for him even if he gets there. Both eyes will be puffing shut and his nose will likely be broken and bleeding badly. Could even be a doctor stoppage in that case.
I actually wouldn't mind that. It would be another good fighter on Whyte's résumé, which would have Rivas, Parker, Browne, Chisora twice and Kownacki. And when he KOs Ruiz and Wilder he'll be worthy of being called Champion