No. They did try. They gave up when they were told they weren't going to get in. They can't sit on a wait list that might open up a week or two before the event. That doesn't give them time to make arrangements to travel to the event, find a place to stay or cover any issues that they might have at home. It might be easy for an OPEN player to sit on a waiting list hoping for a last second spot, but not so much for others.
The lack of a waiting list doesn't suggest a lack of interest in participating at Worlds, only a lack of interest in sitting on a waiting list.
"They gave up" is the pertinent info. How are the organizers supposed to know of a higher than anticipated demand if it is not apparent? Sounds like some division caps were adjusted. They CAN sit on a wait list, it's a choice. Maybe not a great one, but it is a choice. You refuse to put your name on a wait list, you will never get a spot.