Garry's Mod blocks the following commands from being run on players.
"con_enable"
"sv_cheats",
"_restart",
"exec",
"condump",
"connect",
"bind",
"BindToggle",
"alias",
"ent_fire",
"ent_setname",
"sensitivity",
"name",
"r_aspect",
"quit",
"exit",
"lua_run",
"lua_run_cl",
"lua_open",
"lua_cookieclear",
"lua_showerrors_cl",
"lua_showerrors_sv",
"lua_openscript",
"lua_openscript_cl",
"lua_redownload",
"sent_reload",
"sent_reload_cl",
"swep_reload",
"swep_reload_cl",
"gamemode_reload",
"gamemode_reload_cl",
"con_logfile",
"clear",
"rcon_password",
"test_RandomChance",
"plugin_load",
So the answer to your question is, that it was never broken.