Yes, Super Mario Odyssey will be at E3 2017
Super Mario Odyssey was announced at the Switch presentation this past week, but Nintendo didn’t really go in-depth with the game. At E3, Nintendo will certainly have more to say. Nintendo of America president Reggie Fils-Aime told IGN that the title will be present at the expo.
When asked how Nintendo planned the news at the Switch presentation while still holding some announcements for E3, Reggie told IGN that some consideration was given to letting attendees at press events try out Super Mario Odyssey. In the end though, a decision was made to wait until June.
“The only decision that was made from an E3 consideration standpoint was ‘do we show Super Mario Odyssey from a hands-on perspective today versus E3?’ And we’re going to show it at E3. But at least from a Nintendo perspective, there’s no other consideration that is driven by E3.”
Super Mario Odyssey comes out towards the end of this year, so I think many expected that the game would be present at E3. It definitely would have been odd to omit it.