Obviously you can't hook the PS4 up through the receiver and get the full benefit of HDMI 2.0 which your TV supports. But, the suggestion to use an optical cable out of the TV back to your A/V receiver makes a lot of sense. My understanding of the (VERY) poorly implemented ARC is that it doesn't support HD audio, and provides the same level of audio quality as you will get from the optical audio output from the TV.
Benefit of optical from the TV is that if you use smart apps with your TV, you should get audio from them reliably as well, or anything else connected directly to the TV.
I would probably just use the optical output of the PS4 Pro and run it right to my A/V receiver and call it done. Video to the TV, and audio to the receiver separately.