Considering this is 8 minutes, maybe it's an announcement of either one of two things;
1. Pokémon Stars (or whatever they're gonna call it) is announced. Hopefully, this'll be set AFTER Sun/Moon instead of a rehash of the story.
2. Something for the Switch. Easy money is a Pokken Tournament port, but I'm hoping for an RPG myself.
Wasn't there supposed to be a Pokemon Go event? Not to mention there's that mobile rumble game that came out in beta a week or so ago. Plus the details on Marshadow haven't been released.
People wishing for Sinnoh remakes and/or Stars are just setting themselves up for disappointment. Especially given how many other things are currently going on right now and the possibly of another "Animal Crossing Wii U" type disappointment.