Over on eBay a Chinese seller specializing in ponies has 3 of these for sale. The toy is a white Celestia with a simplified design with yellow nylon hair for a tail. This is very similar to what McDonald’s has for happy meal toy premiums.
Thanks to Oak23 for finding this.
McDonald’s tends not to announce their toy premiums farther out than a month in advance. Burger King is currently offering their own FiM toy premiums in Germany and the Netherlands.