What about all those who no longer have premium connectivity. They are more likely to have a music streaming service that works through android auto. That's just one single function too. As we have established mapping is better, and offer more variety. On the phone apps. Plus there is the convenience of messaging. Not just SMS but WhatsApp/telegram/wechat(possibly) I don't think it'd take a massive development. The software most already exist, as pretty much every other car manufacturer offers it now. It'd just be a case of installing it on current infotainment. It seems strange to me that people praise Tesla for their "technology" yet some simple technologies available to all other manufacturers get ignored by Tesla.
I suspect your first sentence is, ironically, one of the major reasons that Tesla will not want to go down the AA/CP route, as it would reduce the subscriber base for the premium connectivity, which must be a pretty decent profit generator for Tesla.