Project Diva series' doing fine on Sony platform, no need to port it to Switch.
I was on the topic of a entirely new game, not a port. I had learned from developing my own game and what's happening now that it's for the better to (no pun intended;) Switch exclusivity: Markets is one thing, when you couple together [Nintendo] Switch's strong sales momentum this time around, the Japanese market's declining interest with handheld systems, the fact that the original [Hatsune Miku:] Project DIVA started on the PSP and being tailor-made for that said market, you'll see why.
Not only that; but that essentially, Switch is what PS Vita's Remote Play features should of been. This is the reason why it's PlayStation exclusive to start with. Soon they are going to make [new] mainline releases Switch-only without developing a 2nd or HD version.
I can go on about things like multiplayer, Nintendo-themed content, and other future-proofing. But there's my reasoning. It maybe hard to stomach by how hastily put together it is, but there you go.