I think you missed the end of the article where any MacOS app could turn on your AirPods microphone without any permissions at all and at any time at all.
No it can't. It's only during Siri commands and dictation. It's not always-on.
Edit: NEVER MIND, that's correct, sorry. Why the heck does the article put the most dangerous part only at the end, and not include it in the tl;dr or anywhere else at all...??
Edit: NEVER MIND, that's correct, sorry. Why the heck does the article put the most dangerous part only at the end, and not include it in the tl;dr or anywhere else at all...??