You mean a software update of course. A hardware update delivered over the internet would be a very impressive feat of engineering, for sure.

Sonos have got quite terse about describing what is in their updates of late.

While the paucity of update notes makes it impossible to know, it likely is just the IDs for the new speakers, like the upcoming Ray, which have to be in the software in order to be able to be recognized by the other existing speakers. 

If you have to read the release notes - means the provider (Sonos) is not doing the job properly! When did you last read an Apple release note - never - it all just works! 

@ITB Message number five that does not ad anything…… Are you building a history to spam us later?

Topic starter does not complain about the working of his system, but just wants to know what has changed.