Why is my pre-order discount not showing on the home/catalog page?

Early Bird discounts are tied to specific purchase options. Since there is no way to choose a purchase option on the home or catalog pages, Early Bird is unable to determine which price/discount to show at that point, so the theme will render the default product price.

Once the customer clicks through to the product page, they will see the accurate discounted price (assuming they choose a purchase option which has a discount applied).