Let me preface this by saying I have more experience with English styles that other European beers so this might not be true for ALL breweries in other countries: While special occasion beers are nothing new... In the 1800's big commercial breweries would create "celebration ales" for the birth of a new royal, the coming of age of a royal, and the coronation of a new king or queen. And while there were also a few beers brewed and marketed for the holiday season these were the exception rather than the norm.
The idea of certain beers made especially for different seasons is a rather recent phenomenon... and driven more by modern day marketing than by any practical purpose. Porter for example was the most popular beer in the world for 100 years or more (Whitbread brewery alone produced hundreds of thousands of barrels annually) and it was consumed all through the year.
This is not a negative statement of the OP or his chart but rather to point out that these seasonal styles say more about the sway that advertising has on all of us than any real reason for drinking a certain beer at a certain time. At the end of the day drink what you want when you want.