Hypomelanism or hypo for short is the genetic mutation that these animals have. When they first came out people called them ghost due to their pale ghost like appearance. To say that a hypo isn't a ghost isn't entirely true, after all there are morphs with the name "Soul Sucker", "Angel of Death" and so on now technically they don't hold true to their names. Now your right in that typically a ghost is referred to when an animal has both Hypo and Axanthic genes shown however in ball pythons this is referred to as a "True Ghost" because ghost had already been used to name Hypos. Many breeders are moving away from the "ghost" term and just calling these animals "Hypos". But to say that a hypo isn't a ghost ...genetically your 100% correct but Ghost is the name the mutation was given based on its appearance not its genetic make up much like "Pastel", "Spider", "Cinni" and so on. Just some food for thought.
P.S a Het Red Hypo would be hot