Well, I figured out why LibRockConfig isn't saving state properly (i.e why the minimap button keeps coming back even if you say to stay gone).
LibRockConfig is using a hack (and not in the good sense of the word) to manage its saved variables - it's overloading the TALENT_FRAME_WAS_SHOWN Blizzard global SavedVariable by appending all of its state to the "standard" meaning of that variable.
Well, that variable is gone in 3.0. So LibRockConfig's state never gets saved.
The icon was fixed WEEKS ago by forcing it to always hide. The data saving is broken and won't be fixed. If you have issues with other LibRockConfig-1.0 settings you don't like, I can change it to be off for everybody if theres a good enough reason.