I believe the "very highly" part is generic (my waitlist e-mail said the same). I imagine most MSTP's waitlists move a fair bit throughout the application period. Because they can only fund as many spots as they have the funding for, they can only put out 8 acceptances at once maximum. As their "top 8" as it were most likely overlaps with other highly ranked school's "top 8" there is bound to be a lot of movement. This is especially true for a waitlist at this point in the cycle (i.e. before everyone has heard one way or another from all of their schools.
Anecdotally, I spoke with one of the current MSTPs there and she said "everyone" her year who was waitlisted was offered admission (obviously she cannot know about those who either declined admission or did not stay on the waitlist).
Hope this helps, I'm in a similar position.
