It indeed is, I just happened to also own a Wave Blue DS4. Kinda a good thing, because the original shell's quality was horrible, and I'm not a fan of finishes that are gonna wear out with time (the one I've got had some marks on the right handle where the metallic finish already started to wear off). So I ended up swapping their shells.
So yeah, it's a GT Sport DS4 with the Wave Blue shell. Kinda feels nice to own something you don't normally get on the market but, at the same time, has no parts that weren't produced by the original manufacturer. Some sort of DIY DS4 Design Lab, lol.