Have you send this observation to Apple?
I think (yes, I guess), in the meantime Apple knows exactly what the reason for the feedback/pitch noise is. Working on a solution? If they can fix it with a firmware update - yes. If it is a problem related to the "construction" then ... probably no.
It might be a "temporary fix" for your specific case (biking for some hours), but really not usable during a flight. The pitches sound comes back sometimes every few minutes. The only "solution" (well, what forked for me), is the 180° thing (without drying or removing something from the AirPods).
To me, I don't really care what the reason is. The AirPods Pro 3 are not usable for the purpose of using them during flights (with ANC) as long as Apple offers not a solution by a Firmware update.