I don't think Mack Rides will say the slightest unless it is in conjunction with MW. Announcing it around the time of the IAAPA Attractions Expo would be a good for Mack Rides if it ends being a rollercoaster that is a global leader in it's field as then, with the global publicity, Mack Rides could gain the benefits of the Expo's visitation, which would be from all over the world. The IAAPA Attractions Expo also fits with the current time period for a potential announcement on the new rollercoaster.
I predicted in my guess timetable that the track parts will arrive in early December so I do think there will be some sort of teaser at a minimum in mid-November like we are all expecting anyway. If they waited until after White Christmas, we might have found the track parts laying around in the car park and from the design & colour of the track parts, we're highly likely to have figured out the theme & rollercoaster features/type before MW even announced it.
Given the hype built around this rollercoaster, I feel MW would definitely prefer announcing it themselves rather than letting the media find out through websites like Parkz this time more than any other previous time. Since Parkz began, nearly all new rollercoasters have been figured out from the arrival of track parts prior to any official announcement. Apart from the Mack Rides crates & the roller coaster DA, MW has kept details of this rollercoaster incredibly well secret and I'm sure they would have realised by now that track parts is an easy way for theme park enthusiasts (and to an extent, the media) to decipher the theme & rollercoaster features/type. A mid-November announcement would be before the track parts arrive ensuring that MW controls and makes the most of the publicity this new rollercoaster will generate.