Slot, a race has to be run for at least a certain number of continuous years before attaining graded status. I think its three but I am not sure.
The Colonial races will attain status once they hit the required years.
Believe it or not the Miesque and the Generous had the same thing happen when they first started out in Hollywood. Even though they drew great fields and hads lot of purse money, they had to pass the time threshold.
Same thing with the Delta race that was just made grade three this year.
In these cases the track or circuit is not being penalized, its that the race has to attain the criteria in number of consecutive years run in order to obtain graded status.