This tactic has proven successful before with the most recent example that comes to mind being Washington Capitals forward
Tom Wilson having his 20 game suspension reduced to just 14 games, a move that saved him just under $400,000 in salary. In that instance however Wilson had already served 16 games of the 20 game suspension, so even if Kadri wins the appeal it he may end up serving the entire thing unless the process is sped up considerably.