When HDMI 2.1 sources and sinks come out, simple: buy an HDMI 2.1 -> HDMI 2.1 + HDMI 2.0a splitter and use your current HDMI 2.0a receiver for audio only. The audio component doesn't need HDMI 2.1 and never will. HDCP 2.2 however, yes, that's important. HDMI 2.0 supports audio-only paths, it doesn't have to have a video signal spliced in.why to buy Receiver with HDMI standard outdated !
I waiting for HDMI 2.1
People have been doing this for years with HDMI 1.4 3D -> 1.3. Yes it's an additional expense but definitely smarter than waiting two years for a receiver which does nothing to the extra ".1" except forward it to your TV or act like a switch.
However, I believe HDMI 2.1 gear will likely be out by next year. In that case, then yes, it might be smarter to wait than spend 2K in 2017, especially if you already have something decent.
IMO all these Atmos receivers are over-priced and under-featured. Seriously, 5.1.2? 5.1.4 is the bare minimum to deliver a proper 3D sound field using point sources.