Casey is still listed as Sat 6-10am on the KOOL site. The show didn't air last Saturday, but that's happened a few times before only to return the next week (didn't receive the feed? Maybe related to Entercom getting hacked?) Do we know for a fact that the show has been dropped?
I would say we don't know for certain as several stations may have declined to pick up the year end countdown. Of course, the end of the year is also the perfect time to drop a show. A lot of radio stations still don't keep their websites current.
I agree with Eric on "America's Greatest Hits." It's not bad; it's just not particularly great either.