Based on this list, to qualify even as a potential replacement for the 7D Mk II some features are lacking.
AF-system
The 7D Mk II has 65 AF-points: 1 high-precision dual cross-type AF point and the rest are still cross-type points.
According to this list the “90D” will only have 45 AF-point. That is considerably less.
Also: no mention of the type of AF-points means that it can be less cross-type AF-points (although that may be unlikely).
More important is the customization that the 7D Mk II has - and that any action camera: the range of AF Areas that can be selected, such as Single Point Spot AF, Single Point AF, 4-point AF Point Expansion, 8-point AF Point Expansion, Zone AF, and Automatic AF Point Selection, Large Zone AF. This, together with the AF Area Select Lever makes it fast and easy to change the AF Area as you shoot. Again, a feature required to cope with changing conditions during action photography. It is very unlikely that the “90D” will get that – why else call it “90D” and not “7D Mk III”.
Controls and Ergonomics
Perhaps a bit less important, but because it is called “90D”, the size of the body will no doubt more resemble the 80D than the 7D Mk II. Ergonomics are important for an action camera, to be able to make available the controls and displays in such a way that that can easily be operated and/or seen. That requires enough room, and therefore ‘size matters’ also here.
Note:
It is quite possible that the “90D” will get dual DIGIC 8 processors. But if this potential is not used to improve on the ability to track and predict moving objects, than this feature has no meaning for action photographers. Especially this is an area where improvements over the 7D Mk II were hoped for/expected.