I'd rather they not do one. I understand the benefits of a PTR, but the negatives are too strong. People can preview content which can greatly affect the primary game on release, and to avoid that they would have to devote programmers to limiting the game just for PTR instead of working on useful projects.

All they need is a little more insight into how people play the game. How western audiences approach gaming is very different from how the Japanese do it, and it's something they need to try and wrap their heads around. They need to make themselves aware of all the cheat apps out there and what their capabilities are. They can easily do this on their own, and for long term success they will need to. No real need for a PTR.