Some New Details
From The Lost Media Wiki
I saw John Waters talk live at a church in Regina, SK (Canada) in June 2017. He actually mentioned Hag in a Black Leather Jacket and his other short films; the primary reason they haven't been released on home video is because they use pop songs that he'd never secured the rights to. He then went on to advise any aspiring filmmakers in attendance to either make their own music, or get music licenses secured right away. Basically, it's legal reasons keeping this film vaulted, though it can legally be screened at festivals if people don't have to pay *specifically* for it (i.e. charging admission to get *in* to the festival, but not specifically to see this film).