it's still a my little pony movie
it's just only focused on Twilight going into this humanoid alternate world, with Spike as a dog (will he even be able to speak?). the other girls won't be coming along though, it'll just have their humanoid counterparts who haven't met a Twilight Sparkle because she never existed in their world
so although it is technically a generation 4/friendship is magic era movie, it's primarily set in an alternate world where things that shouldn't happen are likely going to happen (which, since it's separate from season four, could make it officially non-canon even though i'll consider it non-canon regardless). not really a legitimate pony movie