Without doubt. I was expecting Volk to get destroyed and he was a wide underdog, most experts thought he would get finished. So his stock has to go up from this fight (relative to Islam and absolutely) and Volk was already P4P No.1.
Let's say that Fury and Usyk fight and Fury wins a 7-5 UD, with a significant minority believing that Usyk drew or won. Is Fury suddenly P4P No.1? Of course not: Usyk's 5 inches shorter and 83% of Fury's bodyweight. If it was a one-sided beating for Fury then sure. But Islam looked more fatigued and damaged by the end of the fight, with Volk all over him.
When Islam goes up to welter and gives an elite champion a 50-50 war or beats him then he'll have an argument.