What problem does this address?

The Plugin release process involves currating the release changelog. This is a big task and needs to start as soon as the RC is published. As a result, the RC changelog gets a lot of edits and is probably in a nice shape by the time the stable release comes around.

What is your proposed solution?

As a result when building the stable release it would seem wise to pull through the changelog from the RC rather than regenerate. Obviously the commits made (cherrypicked) to the release branch since the RC should still be included above as currently.