The IAAPA Expo trade show (and therefore the reveals) usually runs on the third Tues/Weds/Thurs and Fri of November.
Any big reveals depend on two things; the manufacturer and the park. If the park is willing to support it and the manufacture can deliver a train (or prototype) on time, they will get plugged.
The press schedule is not usually finalised until the Monday before the show. This is in case the exhibitors do not get their **** together on time.
All reveals are then scheduled for a certain official time to ensure they don't clash. Big reveals (for those who are premium IAAPA members, your Six Flags, Intamins etc) always happen on the first day of the show.
So if you're looking for big reveals, pencil Tuesday 15th November 2016 in your diary.
CoasterForce will be covering this year, next year and beyond!