Interesting. I haven’t seen this come up for our app using push notifications, though the last time we published to the store was back in October.
It looks like Firebase added the required privacy manifest. See [FR]: Support App Privacy Manifest · Issue #11490 · firebase/firebase-ios-sdk · GitHub.
Maybe make sure your Firebase SDK is up-to-date? I think you run pod update. You could also check the version you are on in the Podfile.lock file.