The Volk we saw in the first Makhachev bout, against Yair, and against Max in the trilogy is someone I think matches up very well against Ilia. I would happily back him against Topuria with a fair amount of confidence.
...but are we going to get that same version of Alex? If not, what percentage of him are we going to get? Because in the time between now and those performances he has passed the spooky 35 mark and also been brutally TKO'd. Those two things are both potential harbingers of elite athletes falling off overnight, albeit not as a rule. As I recall no champ at the lower weight classes has ever successfully defended beyond 35. Needless to say, given all of this plus Ilia being a solid, well-rounded finisher who stormed up the ranks... there is definitely enough writing on the wall to have me spooked and give me a bad feeling in my gut, regardless of how I feel about the stylistic matchup.
That said, I'm probably still going to side with Alex regardless as the more proven commodity based on what I do know rather than going with what could be possible. No outcome will surprise me, however.
EDIT: I want to make something clear by adding a disclaimer. If Topuria wins, it is as much by his own skill set and talents as the red flags I'm throwing out about Alex. By no means am I trying to prematurely discredit Topuria's potential victory or make excuses for Volk ahead of time. That's silly. Ilia is a great fighter that I have thoroughly enjoyed watching rise through the ranks. I'm a fan and I believed in him when others didn't. If he beats Volk, it's a legit victory; I am just trying to analyze the fight and all the potential factors that may or may not play into it.