It's a step up for 80D users, but 7DM2 owners are a completely different set of buyers.How do you know using a 90D would be a step down without knowing the true specs yet? My hunch is it will have much better DR than a 7D as well as other improved features, especially if Canon is considering making the 90D an amalgamation of an 80D and 7DII.
If Canon intend to merge both series they would be wise to call this model by a completely new nomenclature.
But they won't, because a 7D Mark III will come out for Tokyo 2020 Olympiad. If it does not, I'll eat my shoe.