I don't know what they did for the newer models or the more upper end ones but I know on the 3808 and lower, if they have multiple side surround amps(A and B) are linked together. The rear and side surround amps are seperately assignable so Denon could allow for height or wide and take away the ability for rear channels while running height or wide.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70