/p biome was removed because of abuse of the Hell biome. It's a feature many of us miss, but it's not coming back; because people would change their plot biomes to Hell, and grief with bed explosions. /p comment, nobody used anyway, but it could probably be re-added. If you mean the /chairs command to enable and disable chairs, there wasn't really a purpose in it; after all, the stairs have to be identified as a chair by placing signs or item frames on both sides, so you can't sit on a plain staircase anyway. Hope this helped!
