Probably when people say that John beating up the Royals was enough for them to have learned their lesson.

The issue has nothing to do with John. It's that the Royals got off way too easy when it comes to everything else. They did the absolute bare minimum to restore their reputation for how they were originally running a god-awful might-makes-right power hierarchy during Season 1, yet everyone is already back to loving and respecting them throughout Season 2. Arlo in particular should have really had to work to restore his Wellston reputation, yet for whatever reason, everyone continued to treat him as their god.

Point is, the Wellston Royals should have had a much harder journey winning back the school than what was provided.