Sounds like you're asking a couple of different things. As to AirPlay, support is unchanged from prior versions. As to ports, Apple eliminated the optical out. This decision is problematic for lots of us -- those with setups such as yours, those with receivers that lack HDMI audio in, those of us who used prior versions of the AppleTV to send music to our system without turning on the TV, etc.
It seems that every year, it takes more effort to remain in the Apple ecosystem. Sometimes I wonder why we do this to ourselves.