If at some point the user had to consent to GDPR, then you could save that fact in local persistence (e.g., SharedPreferences/UserDefaults). Something like a isEEA flag. And then you'd only show related widgets to revoke/edit consent when that's true.

Just had this problem too. IAPs were already approved in a prior (submitted) version of my app. I have just re-submitted a new build (same thing, just bumped build number) and attached a message (and picture) showing that IAPs were already approved. Let's see.

Update: I got it approved now. As I mentioned before, I re-submitted a new binary which was basically just a build number bump. I commented both as a reply to the first review and in that field we can use to communicate things to the reviewer of a new submission that I had the IAPs approved before - and included a screenshot of the IAP screen showing that. It worked this time.