@RawMean Thanks for finding that out, but the question still remains: what happens to me if I do not submit a version and I do not update the age rating, before January 30 or whatever. Is my app thrown off the App Store? Is it frozen forever at the current version? What?

If that's what the letter means, someone needs to teach the folks at Apple some basic English, because it sure doesn't read that way on any objective account.

I feel calmer already!

That does make the junk warning go away, but it's no kind of solution. The fix needs to come from Apple.

I'm doing exactly what you said, and I can't reproduce the issue. Can you post on github a minimal example showing how to experience the problem?