I thought that the qualifying was top 156 and ties, which would mean that anyone who shot the number would have qualified for the event, I believe that there were 170 total. In past years there have been reasons that people could not advance or receive payouts, not sure if this is the case this year. We have also received a variety of things over the years besides just credits. Generally a one year USGA membership and I recall once a British Open hat from the championship and I also think maybe a US Open hat, I think those were so difficult to distribute that they were discontinued.
It also is strange that on the leaderboard you can only see the scores of 135 players, I have no idea what is up with that.