GC- Wheaton Warrenville "The Classics" (BV) (BC) (BB)
1RU- Wheaton Warrenville "Esprit"
2RU- Milton "Choralation"
3RU- Fremd "Soundscape"
I think that Wheaton will be safely ahead of the other groups, but that it will be close between Milton and Esprit for 2nd and 3rd and close bewteen fremd and Nova for the last finals spot.
While I can't speak with absolute certainty, I'm guessing they must as there are only four tier I groups and they are taking four finalists. If they didn't allow other divisions to be eligible, then I'm not sure what purpose a prelims round would serve. Stranger things have happened, though!