While Airplay 2 doesn't appear to have shipped yet (according to Apple Tech support) I have noticed a couple interesting features.
Multiroom support to Airplay speakers, Airport Express(acting as Airplay speakers) and Apple TVs are displayed in the iTunes speaker control panel in macOS. Has been for a while.
I just noticed multi-room support is also present on Apple TV. I have a few ATVs V3 which appears I can select and broadcast to other ATVs or Airport Express units from a single Apple TV. I am not sure when that feature was enabled, but looks like a pretty cool feature. I wonder if this is an early stage of Airplay 2.
My Sound Touch speakers have Airport Express routers attached making them defacto Airplay speakers.
Granted my setup is currently working outside the Sounttouch sandbox, those with v1 or 2 Sound Touch 30 speakers (Airplay built in) and an Apple TV might want to give this a try.