Switch sold pretty well considering the lack of big titles. If Labo is a success and if their holiday is strong enough, 20 million WW in 2018 is still very possible.
No! It is falling off a cliff and losing momentum! It didn't sell well despite no big titles and no MH!
Anyway, on a serious note, sales will ramp up towards the summer when more and more titles release. Coupled with Smash releasing this is year, 20 million is within reach for sure.