Schools always offer more acceptances than there are seats in a class. Even Harvard with an admissions yield of 70% does.
When schools, at this point, says that their class is full, as most of the T20 schools have, it means that they have high confidence that by CTE deadline, all who have CTEd and PTEd, will attend. There will be a few exceptions, as there has been each year, where schools will pull from the WL at or after the CTE deadline. But the numbers here are small.
As has been mentioned, most movement at the T20 schools has stopped and, except for the proviso mentioned above, most movement is over at them.
For other schools, it's a mixed bag Some have underaccepted because of the rules change this year and so will have movement up to and beyond the CTE deadlines. Some have a better sense of there classes at this point and don't forsee much movement.
While there is always hope until classes begin, the window is closing, and so making concrete plans to do one of the following -- attend the school you have been accepted to, reapply or reinvent -- is prudent at this point. Remember most schools can fill their classes 2-3 times over with students from the WL so chances are small of getting off of one.