>>56259154Evolution levels and learnsets only apply to the player's perspective.
As in, Ethan cannot teach Barrier to a Dragonite nor can evolve it at a lower level than 55, but that doesn't mean Lance or anyone else can't. Maybe had the only ever Barrier TM to exist, maybe it requires a special way that the player cannot perform, and evolution levels clearly mean nothing when you can find both underlevelled wild mons and random trainers using them.