Yeah, the UFC prolly just wants to showcase Evloev and give Volk some more time to recover as he is already kinda old.
Dont forget that Volk in his last fight against Lopes injured his eye. It was just two months ago. Dunno how serious eye injuries are, but sure its gonna need time to recover.
When it comes to Volka and fighting in the UFC, he always finds a way to be in the octagon fighting someone, even if he is the reserve. So, it may take a while, but he finds a way to fight, he signs contracts for fights that will happen in a few months. He finds a way to participate.