I can confirm that this month's CoroCoro has a feature on the long-rumored Fairy-type, although the Japanese name of the Type is "Yosei", so I am uncertain if this means that Hiro was necessarily correct.

Sylveon is a pure-Yosei Type Pokemon, and is known as the Maryoku Pokemon, "Magical Charm". The attack shown in the trailers for the Mini-Movie is called Mirakuru Hou, "Miracle Cannon", and is said to heal the opposing Pokemon, yet greatly reduces their Attack and Special Attack.

Clefairy, Togepi, Jigglypuff, Audino, Chansey, Skitty, and Dunsparce are shown with their "Normal" Type changed to Yosei Type. The magazine mentions that a recent event in the Pokemon World has awakened a long-ago sealed power, explaining the Type Change. More Pokemon are said to awaken to this power, hinting at additional Type changes.

A Type Chart is shown displaying how Yosei Matches Up.
- Yosei is immune to Dark and Dragon
- Yosei is weak to Psychic, Poison, Bug, and Ghost
- Yosei resists Fire, Water, Ground, and Flying.
- No Type is weak to Yosei.
- Fire, Water, Ground, and Flying resist Yosei.
- No Type is immune to Yosei.