Isn't canceling the Lights of Winter a breach of contract?
Read the back of your theme park ticket for Disney's contract with you; I believe similar language is used in all hotel vouchers.
They can basically change anything at anytime and not owe you a thing.
From MYW Package terms and conditions - Package Attraction Tickets:
Parks, restaurants, attractions, recreation, entertainment, and other products, services or items are subject to change without notice, cancellation, and may close temporarily due to refurbishing, capacity, inclement weather or special events and may otherwise change or be discontinued without notice and without liability to the owners of the Walt Disney World Resort.