Steep is definitely a bit of Switch vaporware at this point. Ubisoft doesn't talk about the supposed Switch version at all, and fans have no idea what's going on with the game. The best source of info right now is a supposed Ubisoft employee that says the game is still coming, but has no official release date. It's hard to verify the source's claim of working at Ubisoft, but he is followed by some other Ubisoft employees, as well as press members who are in-the-know. I'll leave the final call up to you.
Reminds me of the Rayman Legends release on the Wii U, but in this case i think Steep is already released on the other platforms?