Yeah, I have a feeling that the 7DII is going to hold its current value for awhile. Similar to the 1D IV -- which only recently dropped in value on the used market.I'm still using one. Will probably buy another before they're all gone.
The 90D is a better general purpose camera than the 7D Mark II. But I've got 5-series cameras for general purpose work.
I use the 7D Mark II to shoot field sports under artificial lighting with telephoto lenses. For that purpose it's still a better camera, in my opinion, than the 90D, though each does have advantages over the other for that role. I choose the 7D Mark II for the longer shutter rating, the better build, and the better AF system.