Well, his family has never made any public statements regarding their son and brother. They have neither confirmed nor denied any information that has been stated and verified online, either through friends, girlfriends, or journalists.
I think the appeal of Vance is, for the general population, even with verified accounts of his cruel behavior towards the women in his life, is that with all that, he's still an enigma.
He's like a cipher, an empty slate where people, regardless of the information that has been confirmed, will continue to create a back story for him to suit their own fulfilment.
Depending on the reasons for the documentary; is it a cash grab to benefit financially before interest wanes or are they truly trying to find the essence of Vance Rodriguez?
He held the same interest to me as the Gabby Petito case, although with Gabby we were privy to the last few days of her life, whereas Vance was a total mystery, even down to the cause of death.