I think we'll get all the major releases from 2017, 1st party and 3rd party-wise, and some teasings at biggest projects for 2018, but nothing substantial on that side (like, a teaser for Xenoblade 3, or something like that).
I also don't think Nintendo will be present at E3 in a significant way. They seems to have clearly crossed (like a lot of publishers) this american show from their route.
I also don't think Nintendo will be present at E3 in a significant way. They seems to have clearly crossed (like a lot of publishers) this american show from their route.