Here's what my uncle who works at Nintendo told me:
They [Nintendo] go to E3 anyway and are just denying things to make a giant surprise out of it, a surprise to outdo the Sega Saturn even! It'll be just one not-too-long video, tailor-made for screaming Youtube "reaction channels" stuffed to the brim with announcements.
First they show off ARMS again with some graphics claiming how alive the online community is, ends with a slow-mo punch and cuts to a character in Spla2n flying away into a pool of ink! "Oh dang son those transitions, we in for a good one", the entranced audience collectively realises. Swoosh out from some ink-looking goop out comes.... Mario Odyssey! There's goop in that game too!
Mario runs over some grassy fields, camera pans up to the Sun, pans a bit further... two suns?! Pans down... ohhhhh it's Xenoblade! Releasedate is Thanksgiving, surpreso h8rz! Images of swords clashing in Xeno... or is it... Fire Emblem Warriors y'all! Camera zooms into the face of Marth, we see the sword in first person now but, oh heckity yeah it's Skyrim!
Skyrim Dude looks at the ground at some leaves, those details! Wait, are the leaves alive? It's a new type of Pikmin with "2018" on a can next to it, awesome! A giant alien herbivore makes its way towards the trembling Pikmin... and explodes in a blue flash?! SAMUS ARAN REPORTIN FOR D00TY, PEW PEW PEW lasers fly everywhere, the orchestral music has changed to tacky dubstep now, wait hang on... some of those blue lasers look like... blue arrows! Kid Icarus confirmed?! (They don't show anything else to send messageboards into meltdown), but the camera races along with the arrows and lasers... they're targetting an Arwing!
Team Star Fox appear in hot pursuit of an unknown vehicle in the distance, the tacky dubstep gets an even tackier 90ies rock guitar on top, camera catches up... it's the Blue Falcon ooooooohhhh duuuudeeesss but who's inside? WHAT THE ICE CLIMBERS THAT'S SO CRAY
The audience is allowed to catch its breath as the camera moves to a birds-eye view... hang on a sec... all the characters we've seen so far are converging, they're all headed for a single place that looks suspiciously like an item-less Final Destination. SMA5H CONFIRMED MEGATONZZZZZ
Dozens of mics are dropped from the ceiling, in health & safety concerning fashion, people look under their seats AND it's the first issue of a newly relaunched Nintendo Power! eBay crashes instantly.