The Atmos renderer assumes that Heights are at the very front & back of your speaker layout and Tops are at the ¼ and ¾ points (with Top Middles being at the ½ point).
You currently have your speakers designated as Tops.
Signals meant for the Tops will come out of those speakers.
If you designate them Heights, then the Atmos renderer will re-map those sounds inwards to where it assumes the Tops would have been.
This re-mapping is done by leaking a bit of the front signals to the back and vice versa, so that those sounds phantom image slightly inward (again, where the renderer assumes the Tops should be). After all, by designating them Heights, you told the renderer to assume that these speakers are at the very front & back of your speaker layout. It doesn't know that they're not physically at those locations.
How audible will this be to you? Only you can tell, using your ears & your set-up. Since you've watched M:I:6 and Matrix, play some scenes that have lots of overhead sound. Re-designate your speakers as Heights and listen to those scenes again. Is the difference noticeable? If so, did it sound worse or better or just different (can't decide better or worse)? If the latter, then don't worry about it and designate them as Heights to be compatible with Auro.