Agreed - NECA has the license to do 6" scale Predator figures (even if they're doing f**k-all with the license right now IMO), I doubt Hiya would be able to do it.
It's the same reason Funko POPs for Marvel and Star Wars are all bobble-heads - Hasbro has the license for "figures" at that scale, and bobble-heads are a sort of loophole work-around that lets Funko make Marvel/Star Wars products at that scale without infringing on Hasbro's license.