The HYPO in hypomelanistic means less or under, anything can be HYPOmelanistic if it has noticeably less black when compared to other examples of the same thing. That boa has noticeably less black than most Sonoran boas you will see.
But when we apply the term HYPOMELANISTIC to an animal, a boa in this case, usually that implies that it is genetically predisposed to have less black and can pass that trait on to it's offspring who, in turn can produce more HYPO or super HYPO babies.
So in the first sense, your boa is HYPO, in the second is it a genetic HYPO? Breed it, and then raise and breed the babies and tell us!
Gus