The FIDE Laws of Chess state:
3.7 e. When a player, having the move, plays a pawn to the rank furthest from its starting position,he must exchange that pawn as part
of the same move for a new queen rook, bishop or knight of the same
colour on the intended square of arrival.
Thus it is not "a move played to black's (extreme) disadvantage". It is, as dfan says, says an illegal move but only if black has pressed the clock and completed the move. If he has not pressed the clock and the mistake is seen then he must complete a legal move by replacing the white queen with a black piece and pressing the clock. In that case he will suffer no penalty whatsoever and the only disadvantage that perhaps he feels a little foolish for his mistake.
If it is Black's first illegal move of the game the white queen will be replaced by a black queen and the only disadvantage black will suffer is that his opponent will get an extra 2 minutes on the clock. If it is his second illegal move he will lose the game.