I believe it is a self selection for which division the team wants to play in. If you want to play D1 then you can - the issue will be that you need to invest $ into your program to compete. I would guess the 3 schools in QC and the bottom 3 in the OUA would choose D2.

Now I don't think you would call it D2 as that would kill marketing but perhaps it is simply different schedules with a relegation after every year.

There have been a ton of models on this so won't rehash but simple math could be that U of T would play Windsor, York, McGill, Concordia and Sherbrooke every year, perhaps Windsor and York twice and then 1 game against a D1 OUA team. Something like that.