I get that if you aren't used to setting a certain number of teams, it can be confusing, but as others have said, it does show the number of teams required in each zone. Plus, you should know you moved up a Division, so you should understand what that means. Finally, it's a mistake you should only make once.
With everything else going on and that is needed in game, I just don't think it's worthwhile to even address this. Players should understand the rules and requirements, and if you don't, take your one lump and learn.