Yeah, I had a feeling they'd announce the third versions/sequels to SuMo for 3DS only. The Stars on Switch rumors were so persistent I wanted to believe it, but it never seemed like something GF would do to me. I think the 8th gen will be on Switch of course, but they're going to need some time to figure out exactly how they're going to evolve the franchise for its debut on a home console. I don't think they wanted a port of a 3DS title to be the first impression of mainline Pokemon on a home console. My guess is we'll see the 8th gen titles debut on Switch in 2019, and probably not till late 2019.
On an aside, it is starting to get annoying we can't get a Pokemon Snap sequel on any of their home consoles after all these years. Maybe they will essentially incorporate that into the 8th gen games.