As a Pokemon fan, I've known the Anime of Pokemon to do something like this. Only days before the 7th Pokemon movie came out, it aired on TV. As a result, it made more sales than any other Pokemon movie that was produced.
It is a little marketing idea that several movie companies make. They air the movie on TV, in hopes of great response so that people will buy the real deal. You see, LBT is well known, but when you talk to someone about it, they most likely think of the first movie and not the sequals. Because of this problem, it might be a wise move for them to do this.
Also, the problem might be that Universal won't have it on store shelves in the US until after the TV Series airs. As we know, there are a few charcters that appear in the TV Series that only appeared in LBT 12. It would bring great confusion if they didn't find a way for the public to know of these charcters. So, this could be the answer as to why they're doing this.
Speaking of the TV Series, I bet that there will be a commercial of some kind during LBT 12 to promote the first airing of the TV Series in the US. This would be very much appreciated to see.

Anyways, this is what I think is going on. What do you guys think?