The habs are already super young at center. Danault is the elder statesman, and he's only like 27.
Then you got Suzuki, KK, and Evans down the middle, all in their early 20s. When a center gets injured, whose next? Is it poehling? He's also early 20s.
I wouldn't be shocked if they look for a veteran presence at 4C. Due to injuries and a condensed schedule, I think Evans will still get his games in too.
As for poehling, I think he should be kept in the AHL for now. Montreal is not in a position where they have to rush him up, particularly if they do get a veteran replacement for Thompson.