My money would be on reportorial ignorance but I don’t think either of us would find many takers for the other side of that bet. The general idiocy of “journalists” is a cat that has long since escaped its bag.

Pretty much all ballistic war missiles of more than quite modest range are hypersonic, in the narrow sense of traveling at or above Mach 5 during some part of their parabolic trajectories. The modern use of “hypersonic” also implies ability to maneuver, endoatmospherically, at hypersonic velocities. That is something Iran’s missiles do not do.