At least from the screenshots of emails I read, it stated that old devices won’t get software updates, but will continue to work. Additionally, any newer devices will not get software updates _while they’re on the same Sonos network as the old one_, because they all have to run the same version.
Edit: here’s what I read https://mobile.twitter.com/seanbonner/status/121976046002876.... It very plainly states the devices will continue operating but none of your connected devices will be updated while you’re using old ones.
That's pretty much the exact opposite of "will continue to work".
I’m not sure what more you could expect.