I know this sounds like some obsessive detective shit but this just showed up on my Twitter TL because of how Twitter likes work so I’ll say it: I noticed that, at least with the likes that show up on my TL from following her, Imalou tends to put likes on movie-related Tweets that are legit content, even before it was officially confirmed. For example, she was putting a lot of likes on fanart of the G5 cast when we only had the unconfirmed bedsheets out. I haven’t seen her put a like on any rumors that turned out to be false.
She put a like on the Equestria Daily Tweet about the book name possibly being the movie name. So yeah, I think “MLP: A New Adventure” being our title seems pretty likely!