Maps keep changing, and the problem is that people keep playing the old build. Nothing in a StarCraft lobby lets you force an update.
Bumping the version number makes the save code do it for you. A new build loads codes from every earlier one, but a code saved on the new build will not open on an old one. Once a player saves on the new version there is no going back.
The leaderboard accepts codes from the latest version only, so a standing always reflects the map as it is now.