If it keeps collecting telemetry it could upload it later if it ever gets the chance. Better it isn't collected in the first place.
Good point, but in practice I think the only way onboard data could be exfiltrated is by a dealer while the car is being serviced. If you DIY or hire an independent mechanic, this seems unlikely.
That also means it isn't passed to your phone via android auto / carplay. Phone GPS is much worse than car GPS for road navigation. It's basically unusable.