I think they will have to do something if they want the legacy ballot to continue. When Barlos qualified there were 150 eligible for the first year. They awarded places to 100 and then guaranteed 50 for 2014.
I am imaging they can't make those guarantees if the number of those eligible increases year on year.
On checking the qualifying criteria I can see they have tightened it up a bit because Barlos only needed to have finished one race in the previous 2 years. Now they are saying you have to complete as least one race in both of the previous years