I've been following Ed Roman's site for years. Here's the history of the Blackback pickups- which could be right or wrong, but this is what was on Ed Roman's web site.
Ed Roman took the pickups out of an EB/MM EVH/Axis, and sought to have them copied . He called them black backs due to the black backs on the Dimarzio pickups. Initially, I saw his advertise that Dimarzio was making his Black Back pickups for him.
However, Dimarzio makes the EVH/Axis pickups exclusively for EBMM- you can't buy them from Dimarzio. If you ask Dimarzio for these pickups, they tell you the Tone Zone/Air Norton set is very close, and the EVH pickups are tweaked versions of this set. So I doubt Dimarzio would make a direct copy of a pickup they won't sell to the public.
Roman didn't sell the Dimarzios for long, and soon had Seymour Duncan making them. Whether they are the same design, I don't know. I do know that no one with Black Backs is claiming to get an EVH tone out of them.