That 3DS 2016 rumor is already debunked fake the moment we learned about Pokémon Sun and Moon's existence from the trademark website, because Pokémon Rainbow was listed as a solo title instead of two separate version. The guy who tried to spread the rumor, SuperMetalDave64, even deleted his video on Pokémon Rainbow after Sun and Moon were officially announced. Even popular youtuber, RogersBase, didn't believe in the Rainbow rumor either.
As someone who was a big advocate for it's illegitimacy, it is actually completely real....
1) Everyone 2 set pokemon game has one codename. Developers use only one so no one gets confused. For example, Ringo was the codename of ORAS. Ninji is the actual codename for Sun and Moon and is even in the logos picture url on the site. It meanss rainbow.
2) The reason the videos are gone is because he was C and D'd. My Nintendo news called out Nintendo on the leaks, and they went after metal dave. They've done this with a few people recently.
And let's not even trust rogerbase. He's a nice guy, but his sources are very inaccurate usually. If you don't know, around October, he went on twitter, and "leaked" that he was tipped off that inklings would be the next smash character and revealed in a Splatoon direct. He was cryptic about it at first( not mentioning them by name, bt dropping hints), but he blabbed about it to his friends and they leaked the info and it spread like wildfire. Leading to massive angry and salt when they weren't revealed, and when people realized how stupid it was for Roger to trust it, as there were and would never be, smash announcements of characters, within a direct for a different game then smash.
That steals the show, and thus they wouldn't want it.
Anyway just though I clear that up. Also the last direct had a majority of the leaked titles in it.
And as for it all comes together. I think we are going to time travel. I think we will end up going to iconic scenes throughout the series and stop the evil team from using the crystals in the logos and the legends, from distorting time itself. But that probably won't happen.