This article also mentions the lack of hat:
The website is written in foreign, but here's a translation:
1. EAR HATS
I can’t believe those are not on sale: it is the very first thing I bought during my Walt Disney World vacation! This classic is really missing in Disneyland Paris. And now we know that DLP is planning to sell the Glow With The Show version of this hat (with lights synchronized to the show) for Disney Dreams, I’m even more outraged the original one is still not on sale in Marne-la-Vallée. But other classics are also ignored in DLP, like these lovely Mickey Mouse shaped balloons. They should not only be seen as gadgets: once guests use these historical items in the parks, they contribute to the joyful and elegant atmosphere of the Disneyland park.
Posted by Guy Hutchinson