Zend certified PHP/Magento developer

when can the metadata of a pdf be deleted automatically

I have a student who is turning in all his work from the entire semester today, saying that the program we use for school messed up and he actually submitted the assignments, I am waiting for IT to confirm this, but in the meantime he sent me his work (in PDF form). I checked the metadata in Acrobat, but it’s gone. Super sus. I know that users can edit and delete it, but is there any program that may be on someone’s computer that automatically deletes the metadata of every PDF they make (or other files) like a security program or VPN? I’m trying to cover all my bases before I confront him.