Serebii Update: Pokémon Sun & Moon and Pokémon GO to be shown on Nintendo Treehouse Live @ E3 on June 15th and 16th http://www.serebii.net/index2.shtml
Apparently, the stone in the bracelets is similar to the Synchro ones from the manga
You know, the Rotom is ok. As long he doesn't pull a Navi The region is too big
Hopefully they make it up by having only 30 pokes to caught or less. More and it'll be hassle to play.