Couch co-op, split-screen, hotseat; Kingdom Two Crowns is nice. So is Darksiders Genesis, For The King, Moon Hunters, Trine, etc.
Always on the lookout for other good co-op couch games, especially with a good story, but I feel that they are few and far between. :(
Assuming that they parse everything locally, which appears to be the case, then why would it have to send a constant stream of audio? A small list/packet of keywords of a few bytes or KB once a day would suffice for most telemetry (including ad analysis and other possible spying reasons') needs.
Also, one ought to be able to see the contents of the packets if they retrieve the devices' SSL key for the session, so this should also be falsifiable.