Nintendo haa confirmed that Switch will get a mainline Pokemon game but they haven’t specified any release year or shared information about it.
Emily Rogers has proven to be a reliable source of rumors in the past. She recently shared some information on the reveal timing and release window for Pokemon Switch. She talked about the rumor on her website and confirmed that a reveal is being planned for later this month. This reveal will likely show the title of the game as well which she expects will surprise the fans.
As for the release window, she has stated that the game will launch in 2018 and considering how she seems confident in it, and how Nintendo has raised their forecast for Switch sales, it is entirely possible that we might get a one two punch of Smash Bros. and Pokemon Switch. Both of these are one of the most popular IPs for Nintendo.
Pokemon Switch is reportedly a brand new mainline Pokemon game developed by GameFreaks. It will be a new generation of Pokemon if we can believe the rumors. Pokemon can also benefit from the increased brand awareness after the popularity of Pokemon GO mobile game.
Nintendo is also set to host a Nintendo Direct at E3 2018 where they might share more details on the upcoming projects for Switch and 3DS.