On further investigation, I think this is a bit of a bug. If I try to post anything, even the exact same title and body as the first post in this thread, but use "Privacy & Security" and "Sign in with Apple" as topic and sub-topic, then it flags my body as containing sensitive language.
In the end, I just posted my question to a different topic/sub-topic. I hope someone has time to look into the posting issue, even with WWDC around the corner.
Also, yes. I've now seen several posts (eg 1, 2, 3) from other people having similar issues.
Topic:
Community
SubTopic:
Apple Developers