That's what I thought as well.
All through Sun and Moon Masuda has dropped cryptic hints about aspects such as sun, moon, solar flares, and more. He seems to be using his twitter as an outlet of being cryptic and capturing fans attention until they release new info. Which works quite well imo.
Given the slow pacing of news relating to this generation, this is definitely something that keeps us intrigued to learn what could be coming to the games. It's definitely an interesting tactic to keep fans interested.