https://www.youtube.com/watch?time_continue=496&v=70V9rBd6uL8
This guy has leaked reliable info before, in the video he talks about how GamePass isn´t happening in Switch at least in the short term, skip to 8:00 to listen to him saying it, or just read below:
"There has been a lot of talk out there about Game Pass on the Switch. I'm hearing from multiple sources that is not happening. Let me qualify, that is definitely not happening in the near term. I can't ever say never, because Microsoft wants Game Pass on TV's, they want it on PC's, they want it on Xbox, they want it everywhere with their XCloud stuff, but as of right now I am hearing from multiple people that it isn't coming to the Switch. Obviously things could change and all that good stuff, but yeah don't expect Game Pass on the Switch anytime soon. At least that is what I'm hearing."
