Y'all know nothing about producing or mastering
The folder is so large because it'll contain the 5
Pro-Tools sessions which they'd need to send off in order to master them. Those session folders include all of the audio clips used in the session, plug-in settings, the lot. That's why the folder is so big You don't just send out the final track. Smh.
EDIT: And I certainly wouldn't expect any of the MVs to be in that folder, as they wouldn't even be completed audio-visual files yet if the songs themselves have yet to be mastered. Logic, people.