This is my prediction of releases over the next few years. Should all be within 6 months accurate, unless all the foundries have trouble again:
Mid-2017 to Early-2018 14nm/12nm: Vega Fury, and mid-Volta (GTX 1080 size)
Mid-2018 to Late-2018 7nm: mid-Navi (RX480 to GTX 1080 size), and MAYBE large Volta (if not then Early-2019)
Early-2019 to Mid-2019 7nm+: Navi Fury, MAYBE a later large Volta
Mid-2020 to Mid-2021 5nm: mid-sized successors to Navi and Volta from both companies. And we'll probably be complaining "where are the 8K capable cards" around now