So the ride is outdated because the IP is outdated? What a terribly poor thought.
A great attraction thrives on its own merit, and doesn't benefit from be carried on the shoulders of the latest and greatest franchise.
ToT is/was one of those. In fact, it's such a good ride that many people who've never been to a Disney park know of the Tower of Terror. It's thrived on its own merit. Similarly, hardly anyone knows what Song of the South is, but Splash Mountain is a popular ride. These rides have become their own IP.
By your logic, I guess Space Mountain, Thunder Mountain, the Haunted Mansion, the Matterhorn, the Jungle Cruise, and, Soarin' are all dated, since they don't have any latest and greatest movie IP. They're definitely NOT among the most popular rides... no... of course not!