I don't think VT is necessarily against it because of where they came from, only the best from that former league would remain, certainly not the schools that made them want to leave.
I think for VT, it's more that by being in the north, they lose a lot of geographically close games, something they want to ensure they have for all their traveling fans. They'd love to be in a division with Maryland, UVA, 4 NC teams, Clemson if they could. All road trips would be within 5 hours, the NC trips very close. In the north-south scenario, they only get 1 NC team at most.
I wouldn't think Miami would care too much, but as you mention, probably don't want to have to load up on the Boston, NY, Pitt trips.