Aww, I was wondering if I was just looking at an older version. How disappointing. But I suppose, unsurprising given the conversation here. I'm sure such transitions would be bringing a surprising amount of instrumentation down.
It still probably is as it is now. But there's better arguments to support localization than transitions.
For some reason the localization still requires javascript... (I'm pretty sure the transition could have been done in just CSS as well)