14.16 is released, any luck in improvement?

Short answer no

The 14.16 release was for other things.

See the comment from Corry in the below thread:

Meh. Just updated. Nothing is fixed. 

Well now no atmos on app ,tried Netflix hbo max now says Dolby digital plus 5.1 whats next………. getting tired of this game with sonos

Yup can confirm that Netflix and HBO max on Apple TV are only playing in Dolby 5.1 after this update 

Seems sonos trying to get rid of Arc!!

I am not having this issue. I can confirm I get atmos in both Netflix and HBO Max apps on Apple TV after updating to 14.16.  No real change in the volume level of the arc though. 

Try turning your television off and then back on after the update to get Dolby Atmos back.

That solved the problem for me. Dolby Atmos playing on Netflix and Apple TV now.

I thought the fixes to 14.12 were supposed to be in an upcoming update, 2 updates later and still no fix.

“Upcoming” is quite a vague word, but when an official statement uses such a word you would have expected 14.14 or 14.16 to have contained the fixes.

Instead we have had 2 updates that could have potentially broken more things, going by thier recent track record. Oh well another 4-5 weeks wait or more, and thats if the next update has the fixes.

Mean while for the last 2 months or whatever it was since 14.12 I have an expensive system like everyone else that is not reaching its full potential.

Tried turning off my tv restarting my Apple TV helped get Dolby atmos to play.  Sonos has quickly become one of the worst companies when it comes to updates.  Seems like that their new mini sub is more important than making sure that their current systems are working like their supposed to