Pegula isn't going to get rid of anyone unless Josh demands it.
He's kept Kevyn Adams as GM of the Sabres for 6 years now despite zero playoff appearances and icing one of the worst teams in the league his entire tenure.
I would imagine Pegula likes Beane and McD and has given them both a very long leash despite it being pretty clear that this team is unlikely to win a SB under their control. Strap in folks, they're about to be here for the rest of Josh Allen's prime.