It's very unlikely that Nintendo has firmed up their E3 lineup this early on. A lot of game development can happen between now and June, and there will probably be last minute changes and tweaks happening to the roster up until a week or two before the actual event.
That said even if it is fake and somebody is just giving us their wishlist, it does sound like a pretty safe list of games. I think that most of these titles are guaranteed to come sooner or later although 2018 E3 might be a bit early for SMM sequal (in my opinion). I am also hoping that they do a bit more than just release a Deluxe version of Smash 4, but given how hard the recent entries have been on Sakurai, it might be what actually happens.
Metroid 4 reveal is possible, but I honestly think that if Nintendo wants to truly move the Prime series ahead they are going to have to do what they did with Zelda and make a proper open world game. If this is the case, then we won't see anything more then a short video on Metroid as this will take years of development and this game hadn't even begun development as of last E3. I personally hope that they don't rush this Metroid game, if they just rehash the Gamecube Metroid Prime formula this game will crash hard and it could be the end of this franchise on consoles. Metroid has to remain the sci-fi answer to Zelda and that means the next Metroid has to be to BotW the way Metroid Prime was to Ocarina of Time.