Caveat: the files still contain your account information, so consider that before sharing.
Not my plan to go on sharing, but got curious and went to check, going into a small rabbit hole (adhd ftw)...
Checked at first the M4V videos, then as I got suspicious, the M4A audios, and then the MP3 conversions ITunes does to be sure.
For both M4A and M4V files:
VLC can't find any fingerprint data, at least not with my default install (maybe some fork can?);
Of the fingerprint information, ffprobe can only find the account id metadata, which is the user's email;
Through Okteta, I could find my account's name and my real name.
For MP3 conversions, both seem to lose identifying information.