From the User experience point of view what is the best way to notify app users when OS updates affects the app functionality

I am a mobile application tester who works in the R&D area of the premium German car company. I am tasked with finding a solution to the below issue for our Users.

How would you deal with the situation where your app stops working on the primary target device after upgrading to Android 8 because the hardware used in the car does not support the new Bluetooth stack changes in Android 8?

The new hardware for the car will take a month or two to get released; so until then how can we support our existing customers - any thoughts?

Workarounds tried so far:

Contacted device manufacturer but have been told that there is no possible solution from handset side Push notifications for customers to notify about the issue - we need to do a major app release and it’s not wise to do with the current budgeting needs Our customer assistance policies does not support to reply back directly on the store reviews We cannot stop users from upgrading their device because some of their apps might need the new OS for security reasons.

So is it a right approach to create a notifications area in the app and push some information via backend as and when needed? [PS : Currently our app architecture is not using any backend]