What's sure is that they won't go further than GPU manufacturers, so if those only passed the 14nm mark, we'll wait a long time before we see 10nm or so.
but a better 14-16nm is possible.
I think maybe an improved s9+ next spring or an s11 but either more of the same chips on a lower clock. or a better chip that is still 14-16nm
to see a 10nm maybe 2020 at best.