It says the version is 2.0.849, but there's no such option.

The Minecraft launcher icon in dock, will open a separate window each time you click it after closing the game.

Steps to reproduce:

1. In the settings, tick the "Keep the launcher open while the game is running"
   and "Open output log when the game starts" settings.
2. Start the game.
3. Quit out of the game, [might be necessary to get a crash].
4. Click the dock icon a couple of times.
5. New windows should open, one per click.