Some noticeable breweries missing? Fitger's, Steel Toe, Surly, Town Hall......... Do they usually release a beer list? I went last year, but don't remember.
I've gone the last 4 years, Surly has only been present at the last 2 (didn't pour last year, "Shit's Frozen" sign). I don't recall ever seeing the other 3 breweries that you've listed attend. I've never seen a beer list, only a brewery list. Most breweries do some sort of social media announcement as to what they are bringing.