It's still too soon, but not impossible at all, because Switch is a handheld console. Considering past handheld performance of DS and 3DS. It cat hit 100m, yes. 3DS didn't, though, but I think Switch has far better chances.
God bless You.
My Total Sales prediction for PS4 by the end of 2021: 110m+
When PS4 will hit 100m consoles sold: Before Christmas 2019
There were three ravens sat on a tree / They were as blacke as they might be / The one of them said to his mate, Where shall we our breakfast take?