I can use commands like /ban, /kick, and /stop in singleplayer. It shows up in the autocomplete as well.
/ban works as in multiplayer.
/kick crashes the game, but it does not give me a crash log.
/stop works as in multiplayer.
Environment
Windows 7
Java version: 1.8.0_151
64 bit system
V-Sync enabled
Yeah I just noticed this and came here to report it