My Little Pony: Friendship is Magic - Gone the way of the Peewee

Hopefully only for the premiere. Probably because the plot has a lot to do with cutie marks and Spike doesn't have one, so they didn't want to shoehorn him into an episode where he didn't have any relevance.

Because if they leave Spike at Ponyville every time they leave on s5 I'm gonna be very disappointed.