I agree with that as stated. I just don't see them implementing all that for a one off generation. I could be wrong but I think these are very early rumors for the 2018 iPhone. Just imho though. These rumors are also a lot of recently patented stuff which wouldn't make sense for the timeline given these new phones will be out in ~6-7 months. And they will be producing them in 2-3 I would think. I don't rule out they might change the form factor slightly this year, but I doubt it. Maybe slightly.
I think it will be in-screen at a fixed place, without a dimple. Tech will be the same , but the black glass will be replaced by transparant cover glass, with a drawing of a virtual homebutton in its place in the rumored function area. So the taptic engine creating the illusion of pressing a button will be the same. This will be so on the iphone 8/x model. 7s/plus will use the same homebutton as the 7/plus.
But where will touchid go on the 8/x. I somehow doubt it will be in the virtual/button in-screen.