Question

What term refers to the rise of a style of rock from a small, regional underground scene up to mainstream pop culture and then the style's subsequent retreat?

Answer 1

This is referred to as a Popularity Arc.

It is a musical term that means the rise and fall of a style's popularity though a stage of commercial boom (mainstream popularity) and then once the popularity dies down the style then retreats back into it's underground state or sometimes disappears completely.