He said it in like, 2017, but in that same leak he got a lot of other stuff wrong, here's the whole Nintendo part of that leak:
"There has been pressure towards Game Freak to get Pokemon's 8th Generation out in hopes of a release next year. If you recall Pokemon Stars, that is (or was) real, but all it was was a Sun and Moon port to the Switch, used as an engine test tech demo thing. "
This didn't happen, the only thing that was in Switch was Let's go Pikachu and Eevee, no 8th generation or Sun/Moon port.
"Metroid Prime 4 should have something revealed with some in-game footage early next year from what I've heard. I'm hearing that Direct in January particularly. Bandai Namco is developing the game for Nintendo. I don't know which development studio. "
Wrong again, no news from M4 in the whole 2018, but yes in the fact that Bandai Namco is working on the game.
"There is some kind of new Animal Crossing that they hope to release next year too."
Yes, this happens, but is also not a surprise that it happen, is animal crossing, there is always a new one for each console.
"The Switch's Virtual Console will not be like how it currently is known to be like. There is some kind of a subscription service of sorts in the works. "
I guess he saw the NES games that you receive for paying for online and thought it was a virtual console or something???
"Mother 3 is real. According to my source, it was completely localized and playable. The sad thing that I've heard is that it is being held back for some reason, which all I know has something to do with not knowing which month to release it in. "
Now it would be a good time
"Square Enix is doing The World Ends With You 2 exclusively for the Nintendo Switch. "
This was wrong, but Square Enix actually made a remake of the first one for the Switch.
"Blizzard is preparing a Hearthstone port for the Switch. I'm not sure when this will be announced due to the phrasing, but I heard about this when I went to Blizzcon."
Wrongest of them all, Blizzard itself confirmed that they had no intentions or interest to port Hearthstone for the Switch.