Switch has almost no third party exclusives yet, even though the 3DS had a lot of third party exclusives. Because of that I think there are a lot of third party exclusives still one the way. All of these 3DS developers are actually working on Switch games right now. A good example is Bravely Default 2, which was just announced. I thought games like this would have been here sooner, but apparently going from the 240p 3DS to the 720p-900p Switch is going to prolong development time a lot. It's a big adjustment.
Right now most third party games are ports or indies, but I think Switch has a much richer third party library in its future. That will lead to much greater lifetime sales than 100m. It won't just be first party games carrying the Switch almost single handedly.
I dunno, that would require third parties to pull their heads out of their collective rectums and invest in the platform, something I just can't see happening, with Switch nearing its third birthday and the likes of Activision and Capcom still treating it like it's the Wii U.
Bet with Liquidlaser: I say PS5 and Xbox Series will sell more than 56 million combined by the end of 2023. (And over 130 million lifetime)