I agree he deserves a couple of stars. He's been a realiable Roubaix rider for a long time now, but winning such a race in wet conditions requires all stars aligning (which very seldom occurs with Sep).Honestly, I don't know how he's doing on wet cobbles. But he got 6th in 2018, 4th in 2019 and 5th in the 2021 Tour of Flanders.
He was doing a good Vuelta until he crashed out and is clearly only trying to peak for Roubaix ever since.
So he'll be up there in the mix (barring bad luck), and just a simple reasoning: there are 14 (+ let's say 3 riders from DQS, makes it 17) riders in that list of favourites. It's a bit strange to overlook a constant top 10 finisher (even top 5 and podium). I also think he won't win, but he has a better shot, just going by results, than half of the names in that list (Colbrelli, Kristoff, Naesen, Kung, + I don't see a fading Degenkolb doing well after crashing out in the worlds, I don't see van Baarle doing any better than his best, which was 16th, just because he did very well in the world's...).
The good thing for him is that Van Aert and VdP don't appear to be in top shape, Sagan is declining and DQS has a monster team but no proven winner for Roubaix. Could be the right year for an outsider.