Yes, they race with Kawasaki Ninja 250R's in Thailand, I have seen them a few times at Bira Circuit, I have no idea if they will race them in 2013.
I know that some of the race teams that did race with the Kawasaki Ninja 250R moved to a Honda CBR250R and race now in what is known as the Thai Moto3 Cup, which has little to do with International Moto3 Grand Prix racing, they loosely follow the similar rules, single-cylinder 250cc engine, and no expensive materials like titanium and carbon fiber parts are allowed... so it's basically a one make race as we have not much other 250cc single-cylinder engine sportsbikes in Thailand. I remember that I was informed that one team was working on a modified Kawasaki D-Tracker 250 to compete in the Thai Moto3 Cup... never hear from them again...