I'm not entirely sure if Fifa would be there, but it wouldn't be too surprising. Those games do sell a lot.
Unsure about Pokken as well, since we just saw quite a lot of it, but I wouldn't be too surprised by it either.
Zelda DLC might get a passing mention, but they're not going to dwell on it for too long.
I'm expecting Virtual Console to be detailed at a later date, tbh, as much as I do want them to get it out already. I used to think this would be the time to talk about it and maybe even launch it, but since they pushed the online service to 2018, I feel like VC was probably pushed as well, since classic games were tied to the online service.
I wouldn't expect any new Nintendo IPs this year.
I really don't think we'll see anything new from Platinum yet.
Pikmin 4 I would almost say is probable because of how long it's been in development. It's only a matter of if it will be pushed to 2018 because of marketing reasons or not. I think it's slightly more likely than Retro's new game, which to me is balancing on the line of "probable" and "possible".
I really want Animal Crossing, but I don't think that's happening either. I predict it's going to happen next year.
Mario Maker DX/2 would probably be ready to go, but they probably want to push it to next year to pad out the release schedule and to avoid droughts. We're already getting a Mario this year in the form of Odyssey.
Metroid is possible, but I would be very surprised if there was an entirely new entry this year. Prime 3 has been teased so much that I expect we'll get it before 2020.
My gut tells me that Kirby would stick to 3DS if there was one this year, but Nintendo has stated that the showcase will only be about Switch games, so I find this doubtful.
I would love to see what Sakurai's been working on. I'm hopeful, but not expecting it.
I don't think MK8DX will get DLC.
It's already confirmed BG&E2 won't be seen at E3 this year.
Other than that, I more or less agree with you. Here's hoping that Nintendo surprises me positively.