I don't see any of the former Montana players listed on CFL rosters. Thought Dante Olson and JLM were with Edmonton, Dalton Sneed was with Winnipeg, and Travon Van was with Ottawa. That's off the top of my head so could easily be missing somebody, as well.
My first thought is maybe it has something to do with the border closure but I saw some articles from June saying the CFL was only requiring a 7 day quarantine and passing 4 Covid tests for returning players and staff to be able to participate in the mid July training camps, so I'm not sure what the deal is for the Montana players.