I don't know. It had the best launch library of any platform ever. But now Zelda, Mario, Mario kart, and Splatoon are all hit and reloading. You can walk into any store and buy a Switch right now. What sort of person buys a Switch now??? They would be a person not swayed by all those awesome 2017 games but what, KIRBY is the game they were waiting for? Smash has its fans but most Smash fans are Nintendo fans and very likely bought Switches in 17 to enjoy all the hype trains. Smash will be a system seller to some degree, but I don't think that much. Pokemon is probably the next real console pusher they have. FE and Metroid too. Switch will have games, but I think it's going to start feeling like WiiU, with only 1 maybe 2 really meaty releases per year, plus a TON of indies. Switch is a far better platform than WiiU, but I think it loses momentum this year. No Monster Hunter hurts really bad. For the next 6-9 months I have no games (besides indies) to look forward to on Switch and that wasn't true for ALL of 2017.
So yeah I think Switch goes into a dry spot in 2018. It will never be as bad as WiiU due to great indie support but it will be bad this year and gamers will start to sour and fans will get more defensive and aggressive in their promotion of lets be honest B tier games like Kirby and Yoshi. 2019 Metroid, Pokemon, Smash all hit and Switch looks good again. Maybe even switch Pro and MHW port. Oh yeah theres Labo this year which will keep Nintendo as a company in the spotlight and absolutely sell switches.
75 million is my guess.