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.

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.

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.