That's the big game at the show, yes. But that doesn't necessarily mean they won't have stuff in the direct. Looking at the rumored releases, Fire Emblem, Metroid, Pokemon, and Bayo 3 will likely get some time. There will also be surprises of other games, sure. But pretty certain they will be releases in 2019 at the latest. Zelda is likely to be a 2020 game, if we are lucky.