Sonos doesn't do Ace release notes. It's frustrating  but  I'm told through customer support that they can't effectively translate the technical details of the tweaks in a way that we'd appreciate. I'm also told they're still working on getting TrueCinema ready to roll out, at some point. 

Ugh that’s about what I expected and sounds like a canned response from Sonos as even some high-level notes like “Fixed static sounds” would be helpful. Really regretting my purchase of the Ace and it’s convinced me to not upgrade my Sonos home sound systems.

They will probably be on Ace gen 2 before true cinema is ready. 

Agreed release notes would be nice, but the absence of these do not make me regret buying an Ace. Why would it?

Simply because it continues to show lack of good faith from Sonos. After the bungled app update they had committed to additional transparency and communication. That app launch coincided with the Ace release, which one would assume would mean that clear communication would extend to this product line. I can only assume there is at least one product manager assigned to the Ace line who should be able to articulate what work is being done on the product via each iterative software/firmware update. 

With this lack of the most basic of communications around product lifecycle development, it’s clear that Sonos is still yet not able to make their commitment to their customers on clear communication.

May be best to put it this way - my litter box has release notes - my $400+ headphones do not.

Does @Sonos support monitor these forums? Any chance we will ever see release notes? 

This is a users community, for users to help other users.  Sonos does moderation, and sometimes the mods comment, but that is not their primary function.