But the "Arcade Edition" package is just a Game of the Year edition anyways - Base Game + Arcade Edition features (free) + S1 characters + S2 characters. It's mainly for people who don't have the game yet, heck it wouldn't surprise me if S1 and S2 characters were just codes for their respective season passes.
Someone who has the base game already can just buy S1 and S2 season passes and they'll be in the same position, they still get the Arcade Edition features for free once the update is up. Of course this won't be the most cost effective way to do it though once the AE package is released.
It's not like SFVAE is a separate game - it's just the game plus season passes packed in one go, probably updated with the new features.