... says:
Basically, the launcher doesn't reflect what options the game is giving you now.
eyebo says:
They're stuck on high because the other options are no longer valid. They've removed the lower shadow settings.
Those other options will eventually be removed from the launcher I'm told. The same is probably applicable for lightmap quality in the compatibility area of the launcher. You can no longer turn off lightmaps either (you could in a very early beta).
Basically, the launcher doesn't reflect what options the game is giving you now. Just hang tight until they update the menus of the launcher, probably in the next update.