I should be able to make a seasonal character and go into the expansion campaign if I want. Blizzard could gate the seasonal questline/content, so that it doesn’t appear until after the expansion campaign is completed, like they originally did with the base game and season 1 (maybe it still works that way if you don’t select skip campaign?) but forcing players to have to go through the expansion campaign with an eternal realm character, which then instantly becomes obsolete, is a terrible idea.