Yap, that seems to be the case. I never bothered with Entune, and not getting any of notice they are talking about here. Still, I am not missing anything.
This is an Entune Apps software update. Media stuff; Pandora, and the like. It uses the Entune App on your smartphone to get to the Internet for the download. This is true even for the Advanced, which has its own cell phone; the built-in cell phone on the Advanced is only used for low-bandwidth telematics, such as the Safety Connect emergency response and the Advanced Entune apps such as charge management and vehicle location. Updating the system software in the display unit is a different process, which can only be done by the dealer over USB. And updating the map database is yet another process, which I think still has to be done at the dealer over USB. All this changes in Entune 3.0, which uses the built-in cell phone for map updates and the like, but that is different hardware for a future model.
I would suspect this update has nothing to do with functionality and everything to do with GDPR coming into force. The General Data Protection Regulation is an attempt to enforce better rules related to privacy and use of your data, and although it's intended for the European Union, in practice the sites and software affected are worldwide distributions--that's why you've been getting (I suspect) a bunch of emails about privacy protections. You've also, if you have a smartphone, getting new versions of almost every app on it, only to be able to present a new series of terms you have to agree to. Anyway--that's my guess.