I think they meant bump up to the GTX 1080, and does it make sense to get a better CPU before getting the 1080.
I think you should get the 1080 now. Run your games and see how your performance is. If you need a better CPU, which I doubt, then you can get one later meanwhile you enjoy the improved performance. If you get a better CPU now you're still stuck with a 1050 Ti. How does that make sense?