My guess is that you ran across a word that the world chat / game filter determined was vulgar. One example someone else raised was spelling the contraction of "he will" without the apostrophe. Or maybe you mentioned shiitake mushrooms but only used one i? Either way, it appears that Z has instituted some automated bans for filtered language, but people aren't being told by the system why they were muted.
I imagine it's just a one day mute, as that is the standard auto-mute/ban.
Just guessing.
Just Manfred