I've flown the route from Tokyo to Singapore many times, they do have it in some areas along the way, Hong Kong area has it, I don't think they have it in Malaysia, but without looking at the charts I can't recall exactly who does and who doesn't right now. I'll take a look after dinner.
Here's the regular route, Delta is now running a 767 on it, which is why it's been about 6 months since I last flew it.
This route is out over the water more than the previous route. That could be because of weather along the route. There are typically a lot of thunderstorms down that way, more so the closer you get to the equator.
