Do note that Pokémon has been at Nintendo's E3s since 2013
2013: XY Fairy-type reveal & Roundtable
2014: ORAS gameplay reveal
2015: Dungeon
2016: SM trailer, Pokémon reveals & gameplay demo
2017: Reveal of Switch games
2018: Let's Go Poké Bal Plus Mew News
2019: SWSH Nessa, Yamper & Impidimp and community apocalypse catalyst
So I expect something here at least
Note: This is not indicative of insider knowledge
legends footage on a Pro would be sick tbh