For a player's entry-level contract to slide (skip over a year), that player needs to play less than 9 games in an NHL season. For the case of Matthew Poitras, he would need to be returned to the Guelph Storm of the OHL, which would make him ineligible for a call-up.
Bruins head coach Jim Montgomery has now confirmed that Poitras, a 2022 2nd round pick, will stay in the NHL for the rest of the season.