Many times it is a week or more behind the release of the actual code, and they don't allow you to enter the code, they give you a special link to follow - off the front page of disneyworld.com, see the box on the middle right that says Savings and Offers - Get Free Ticket Upgrades with your affordable Disney vacation - click there.
Not necessarily - for each code that is released, the website needs to be 'reprogrammed'. It's only been relatively recently that the disneytravelagents.com starting getting the ability to book these codes online - many times we had to call in too to be able to use a discount code.
I think they first reprogram the CRO computers, then they do the TA site, and then they release the special to the public site - and even then - I think the most accurate information comes from the CRO computers.
Maybe someday they will enhance their web booking engine - I love what they did with the cruise booking engine!