The event was prerecorded. It doesn’t seem farfetched¹ to think they already had the approval but legally couldn’t say it without the FDA making it officially public. But if the FDA had announced it before the event, it would’ve stolen the surprise. Not only of the feature, but that new AirPods would be announced. Apple would’ve hated that so they may have asked for the announcement to be delayed.
¹ Maybe it is. I’m not an expert on the USA’s health and government policies.
The approval process requires steps on both sides; Apple could've just delayed sending the last bit of finalising paperwork until they were sure it would drop after the announcement.
apple actually didn't release any 'pro' airpods at this event, the feature is for the pro 2's which have been out for over two years now, was glad it wasn't made a feature only for a new version
¹ Maybe it is. I’m not an expert on the USA’s health and government policies.