Just received the legacy email that tells me that half my 10 unit system will be obsolete from May. So it appears that I can either pile more money into Sonos, accept that my modern equipment (less than 2 years old) will no longer be updated because I have the audacity of being a long term customer or go somewhere else.
So I can make an informed decision Sonos must now publish the support windows for all products currently available. At least try to recover some credability.