Their regular season ends the 21st if I recall.
After that, I think the Habs will only be allowed to recall a bunch of them up to the big team once the playoffs start as their Black Aces.
Players on PTO's like Hudon, Archambault, Vail, Collberg won't be able to participate. However, it's more than likely that you'll have Beaulieu, Tinordi, Leblanc, Dumont, Pateryn, Bournival and a few others around the team.
I think Kristo can be called up as a Black Ace as well, similar to what Mark Stone did last year with the Ottawa Senators. But maybe they changed it with the new CBA, who knows.