I get matching the aesthetic. The CX-A5000 did not get the Atmos update so it will have to pull duty as an amp. If matching the aesthetic is an issue, I'd get the eARC supporting RX-3080, if it can be found, to pair with the already owned CX-A5000. New PCs and game consoles supporting 4K @120Hz can be connected directly to a new TV and use eARC to passthrough lossless audio to the RX-3080 via eARC.
Excuse my confusion as I kept thinking of the CX-A5000 as a receiver and not processor. Updating to an Atmos capable AVR makes the CX-A5000 useless here. So, RX-3080 would be my suggestion if RX-A6A is off the table. Not sure about the amps already in the system but
@AcuDefTechGuy mentioned the perfectly suitable MX-A5000 to pair with a new 11 channel processor.