My impression from the layout/what we can observe of the show elements that it's somewhere between Slinky Dog and Hagrid. Multiple launches and show scenes/animatronic figures. That, to me, constitutes a headliner not unlike what Big Thunder is to Frontierland -- not necessarily the biggest ride in the *park*, but certainly one of if not the premiere experience in its themed area.
I don't disagree that a flight simulation ride would help flesh out the land in the future, but I just don't think it's fair to say the land doesn't currently have marquee attractions.