The shuffle commands are now application properties. Back in the day, each playlist could be set individually via AppleScript to shuffle and/or repeat. Those were deactivated when playlists were re-vamped under iTunes 11. At the time, shuffle and repeat became global settings and were no longer 'scriptable.
Well, they're back. But not for individual playlists, just as global settings. The new properties are shuffle enabled (taking true or false as values) and shuffle mode (songs/ albums/ groupings). The new song repeat property takes the old off, one, and all parameters.
[UPDATE: To be clear, the obsolete shuffle and song repeat have been removed as playlist properties.]