You won't lose the AX capability. The AX92U, like the AX11000 has the same radios. I am running one as a Media Bridge since I can't do an Ethernet Backhaul and I am using an AXE11000 which only has one 5 GHz and one 6 GHz radio along with the 2.4 GHz radio..
A wired Ethernet backhaul is usually a good way to go but both the AX11000 and AX92U can use one of the 5 GHz radios for that. The AX wireless speeds are higher than the 1 Gbps Ethernet connection. Since I don't have that exact configuration, I cannot tell you if the 160 MHz bandwidth is available on both 5 GHz radios..
Maximus Z790 Hero,