Oh I gotcha. Yes, speaker remapping.
It sounds to me like Atmos is doing that, or something like that.
Nope. Atmos doesn't do any speaker remapping; it places sounds based on cartesian coordinates, with certain predefined locations for some objects to represent channels within an object-based context. Here's the logic:
1. The forwardmost speakers represent the 0.0 longitudinal range, and the rearmost speakers represent the 1.0 longitudinal range.
2. The leftmost speakers represent the 0.0 lateral range, and the rightmost speakers represent the 1.0 lateral range.
3. The ear-level speakers represent the 0.0 vertical range, and the height speakers represent the 1.0 vertical range.
4. If only 2 height channels are available, they represent the entire range 0.0-1.0 longitudinally. If you have 4, the forwardmost are 0.0 and the rearmost are 1.0. If you have 6: 0.0, 0.5, 1.0. And so on.
So, for example, if you have 5.1.x, the surrounds actually represent the back of the room (which is why surrounds are placed further behind the listener in this layout). If you have 7.1.x, the rear surrounds represent the back of the room and the side surrounds represent the midpoint for rendering purposes. So you still have to ideally put the speakers where Dolby has dictated they should go for any given layout.
What speaker remapping does in this context is try to correct for when speakers can't be placed at those ideal positions. But again, this isn't a thing for the overwhelming majority of Atmos systems, which simply rely on the above logic.