Stars/Eclipse is quite possible on the Switch actually, for the exact reason that there has never been a true mainline Pokemon game on a home console before: The Switch isn’t a traditional console. It’s only slightly less portable than a 3DS, has infrared and can communicate with other Switch consoles locally or online just like the 3DS, and even has touch sensitivity.
Whether Stars is real or not, the important thing is that it’s more likely for there to be a mainline Pokemon game on the Switch than it ever was on any of Nintendo’s other consoles. It’s a hybrid handheld-console, and honestly the bulk of the work is already done, the graphics would just need to be upscaled for HD, the controls and mechanics wouldn’t require any changing.