Don't recall seeing WC for the 'john' in Europe on my last visit. some time ago. Ladies, gentlemen, toilet, lavatory, Damas, etc., etc., but not WC.
The abbreviation seems mostly used now for World Cup or Weather, Current.

Would someone from UK or the continent comment on this momentous enquiry about current use for loo (the instrument made popular by Thomas Crapper), a word which seems to have lost currency?