I have no idea what sort of timeline Apple is on or what sort of action they’ll be taking. I haven’t heard of anyone changing the graphics card in their Mac as a way to solve this issue and I don’t know how successful it might be. There’s several threads on this topic already and in one, the SketchUp folks are collecting graphics card info from Mac users seeing this issue. I’ll see if I can the link to that thread.
ETA: Read this: Layout question 2017 version - #5 by Anssi
and also this: Black areas showing up in 2017 Layout viewport - #27 by Marc