Many thanks for your comments ST30, I do appreciate them and await BOSE's comments before plunging one way or the other...I am nervous, hence the post.
If you are trying to add (preserve)your older Wave Radio to a SoundTouch Network a wireless link adaptor will do the job. Indeed if you want to add a Smart Home 500 speaker to a SoundTouch network, you can add a wireless link adaptor as well.
I don’t know if Airplay will be added to the SoundTouch adaptors in 2019.
Another way you can do this of course is add Airport Express to each speaker. It’s not SoundTouch but you will get Apple Music, iTunes library and your iMac in the game while preserving your Wave radio. Apple’s multiroom is pretty good when using an iMac and Airport Express.
Frankly, sometimes trying to preserve one speaker and combining new standards with adaptors can get very costly, compared to just starting a new.
Hi Bose, are you still ignoring us? when is Airplay 2 support coming to soundtouch equipment? the Bose 650 is a 4,000 USD piece of audio equipment. How can you still be 'working on it'? So now a $500 Samsung TV will have Airplay 2 support while we still wait on you to either bother answering conclusively with a timeline or a statement about how you will not support Airplay 2. https://9to5mac.com/2019/01/08/airplay-2-tvs/
Thanks for posting. We aren't ignoring you! The information I have available to share is the same as you will find in other threads. We are committed to bringing AirPlay 2 to both our Smart Home speakers and SoundTouch in 2019. That's as specific a timeline as I am able to provide. We do appreciate your patience and look forward to the benefits of integrating one of Apples most popular features.
Greg - Community Support