Once disembarkation starts, there is, IMHO, no problem in letting people off the ship, and I certainly did not see anyone queueing at the gangway, nor indeed anyone turned away because their coloured tag had not been called. In fact the downside to arriving too early in the baggage hall on ships that do provide fresh baggage tags, is that your row is still full and takes you far longer to find your luggage than disembarking a little later, when it's much easier to spot your suitcases.