The argument about privacy is a bit of a red-herring IMHO. The audio should be recorded for each flight plan (whether one segment or multiple) in its entirety. The system can automatically delete all recordings finished N or more hours ago on next power up (say 6 hours).

In a crash scenario obviously power will be lost at some point and not return so the data is safe.

In a malfunction scenario standard procedure would be to pull the box before powerup so even if maintenance doesn't get to the plane quickly or the pilot's incident report arrives after a few hours the recording related to it is still present and maintenance can go back and grab it. Or for scenarios where a malfunction beings on the early part of a multi-segment flight plan the data would still be available.

But for pilot privacy the recordings are not held forever. During normal operations the plane will be powered down, eg while parked in-between flights, and when powered up older recordings get truncated.

All telemetry should be streamed to a cloud service in real time. Absolutely no reason not to do that. No one should ever need to "search" for a plane or wonder what happened to it.