[https://apps.fcc.gov/oetcf/eas/reports/ViewExhibitReport.cfm?mode=Exhibits&RequestTimeout=500&calledFromFrame=N&application_id=427834&fcc_id|Here is a link] to the FCC filing.
When you read the various papers submitted for peer review by various Disney research organizations (including Imagineering), it becomes pretty clear that Disney's plan is to utilize the bands to track each and every guest in real time, and offer various incentives on the fly (bonus fastpasses, reservations for tables, etc.), to distribute crowds throughout the park more efficiently.
Think air traffic control for people.
