Ray's strong but easy to counter. I don't think I'd be able to call it a great pick for worlds until I know the exact meta. Like of malamar techs one wobb, you just lose instantly going second. And Zoroarks could tech heavier parallel and fairy techs. Its not a fan of black ray either.
I feel like ray wants to sneak in under the radar, but that might be hard to do given its performance in Japan. I think if a ray deck does well, it'll need to run a few unexpected rogue techs that answer its counters.