I called BMW Genius today as well, they told me so long as a vehicle is CarPlay capable any model from 2017 to present will get the service for free. They said you can check your CarPlay status by logging into
BMW ConnectedDrive
and look under 'Subscribed services' for CarPlay. If you don't see it there and CarPlay is instead listed under 'Recommended services for this vehicle' try to reset iDrive and see if it gets updates.
Resetting iDrive- Make sure the car is on, engine running.
- Reset iDrive by pressing and holding the volume knob for approximately 30s, when the screen goes blank let go. iDrive will then reboot.
If you still don't see CarPlay enabled for life call BMW Assist for further help, 1-888-333-6118. They also said this announcement just happened yesterday, so be patient. It may update on its own.