If you get in around your ADR, you should be fine. At noon, we have gotten right in and also waited 20 minutes.
In general, from seating time to leaving, we are there about an hour. That would put you headed to Fantasmic about 7:15. You most likely, will find a long standby line to join, but shouldn't have much trouble getting a good seat.
A mentioned, because you could wait a bit to be seated, I would try to get an earlier ADR if possible.