In my experience AirPlay equipped receivers are also a pretty decent bet for long term support. My receiver is a 7 year old midrange Marantz model and its AirPlay has always worked great. It still gets software updates occasionally too which is nice. If I upgrade it’ll be due to changing HDMI standards (it can’t handle high framerate 4K video), not protocol support.
As I understand Airport Express models from the 2000s still work with AirPlay from modern Apple devices too, though I don’t own any and can’t vouch for them personally.
As I understand Airport Express models from the 2000s still work with AirPlay from modern Apple devices too, though I don’t own any and can’t vouch for them personally.