It's not just
free dining, it happens with everything even back to pre-dining plan when everyone was holding their breath for AP rates because it was better to do room onlies so lots of people got 1 AP for the discounts. It's a cycle.
Someone starts a code watch thread months before any code release would be expected. Lots of people subscribing and posting "me too! I want a discount!" Time goes by and it gets closer and the excitement builds.

The closer it gets, the more the panic begins to set in. Lots of doom and gloom...there are too many people booking non-discounted rooms and they are ruining it for the rest of us! Disney doesn't care about us, their most loyal guests of all! No discounts! Panic and fear! Threats to cancel! I'll never go to Disney again! I'm so offended, I'm writing a letter!
Then about a week after panic ensues the discount is released and everyone says they knew it all along.
Rinse and repeat for each new discount release.