Something definitely happened, now I don't have to force/select 5.1 dolby on my Apple TV 4K before playing 5.1 dolby. Now SONOS itself switches over to 5.1 when supported playback from my Apple TV.

If you are using an Apple TV 4K with a Playbar, you should set the TV and Apple TV to these settings and it should hopefully fix your lip sync issues:

Samsung TV Settings:

HDMI-eARC Mode: Off

Digital Output Audio Format: Pass-Through

Apple TV 4K Audio Format settings:

Change Format: ON

New Format: Dolby Digital 5.1

When it comes to optics, you can't choose the settings, however Atmos can be set to off, but again only regarding HDMI.

The changes on Apple TV 4K are exactly what I am mentioning, it is no longer necessary as SONOS itself switches to 5.1 Dolby, even if this is not selected/forced through on Apple TV. As I had previously activated otherwise, the SONOS only played stereo PCM 2.0.

This probably is just an interim update and unfortunately it doesn’t include fixes for the known Era Bluetooth problem and the Era100 Alexa problem. For this we have still to wait. 

Interesting that there is (yet?) no update to the controller. Wonder why the release? With no controller update, we are even less likely to get update notes…but now I need to go look to see. I might be wrong. 
 

Edited to add, this is S2 information. I’m not sure if S1 has a similar firmware update. 

Indeed, no release notes. 

@Airgetlam

S1 has got the same… firmware update without changing the version number (just built number) and without controller update. 
So probably really minor changes like security fixes etc. 

 I do agree….but which security fixes? . Probably better not to detail them, so the unscrupulous won’t take advantage of those who haven’t updated yet….but Apple (as a for instance) is pretty good about letting me know when they update iOS and MacOS. 
 

I still wish there was a post.