It's beacuse they were still pros when they posted those scores. Even if they move up a tier after they play in a pro tourny, their scores will still count in that tournament. (It's even possible that the score they posted AS a pro in that tournament was low enough to move them up into the master tier.)
Wouldn't be very fair to anyone if they shot a great round in a tournament, then got DQ just because they moved up a tier.