I think its a creative and a good idea. Many travel companies are doing similar things. Specifically I'm thinking of hotel chains and airlines offering deals to buy discounted points or miles. That's to bring in extra cash during this period when their regular revenue is way down.
I think there are two reasons why Disney wouldn't do it though. First, it's a hard task to make people aware of a one time event, and it takes time for people to evaluate it and make the final decision to buy. This kind of promotion would need an end date or else the other people (blue card holders) start getting mad that one of their benefits is being offered to non blue card holders.
Second, Disney hates giving discounts. They're like Apple; they almost never give a discount on any product that is still selling at full price. And even though Disney could probably use an extra cash infusion, I don't think they actually need a cash infusion. They're well capitalized and they're well positioned for the future. They own tons of content, and I believe that today content is king, more than ever before. Also, I don't follow the stock market closely, but I think their stock is doing very well, and for the most part, that's the only thing that CEO's care about today.