That's true, but the Ramza/Alma hairstyle isn't a seasonal/timed event. The Ivalice raids will always be in game, but the XVI crossover will end in May.

Like I said, I don't know of any previous seasonal/timed events that just sold their rewards through a normal vendor. I only recall seeing them added to separate vendors, and those vendors disappear when the event is over so you can't purchase the rewards anymore. When the event is over are they going to remove the ability to buy the Clive card from the Triple Triad Trader? Or is it going to be purchasable as long as you finished the quest in time? And the same goes for the orchestrion rolls from the Prize Attendant, do those vanish once the event is over or will the stick around as long as you've cleared it? Since I don't know of any previous example of a timed event reward being added to an already existing vendor, I don't know what the precedent is for this case.