It'l be okay, because if Freeza becomes the main villain again, the henchmen will just wish em back to life even stronger, or it turns out he has another final form now from training with all the dead villains for so long.
If there is a show that can pull off bringing back the first major villain and deal with the power creep of the protagonists, its DBZ. Their solution for GT was to just make Goku artificially weaker just because (is GT not canon? Idk anymore).
Their solution will be silly, but should totally work in the rules set by the rest of the Dragon ball Z content