So after a long time Airplay 2 finally became available for SoundTouch speakers.
Sadly, the Wireless Link Adapter was excluded.
In an effort to support the majority of products while ensuring high-quality audio playback, we made a decision to release the firmware to support products that have fixed audio latencies. Our line of SoundTouch Wireless Link Adapter and older Lifestyle systems have latencies that vary depending on connected accessories, which makes it hard to guarantee your audio will stream seamlessly and synchronized with all speakers in your AirPlay 2 group.
I have the SoundTouch Wireless Link Adapter hooked up to an old Bang & Ofusen stereo and I was looking forward to stream some music from my Mac to it, using Airplay 2. So latency wouldn't have mattered in that case as I wasn't going to group the adapter to other speakers.
If in fact the latency-concerns are the only reason why Bose excluded the adapter then I think it would have been much appreciated if they had left it to the user to decide if some latency is acceptable or not. Apple provided Airplay 2 for their 2nd gen. Airport Express and Sonos offers a similar solution as well. Both of them also can't predict the latency of connected speakers.
Should the SoundTouch Wireless Link Adapter be missing the necessary hardware to provide Airplay 2, then it would be nice to just have this confirmed and we can put a nail in that coffin.
If anybody else was waiting for Airplay 2 on the Wireless Link Adapter and could live with potential latency issues, let Bose know below. Maybe we can get more information about this from them.