I didn't hear about that until two days ago. That's really unfortunate as I would have definitely plan a different weekend. Why does the whole state go to Disneyland?
It's not just that one weekend. It's been like this every week since the 60th started.
Every week some minor contingent from some lightly-populated Western state can come forward and claim
they are the reason that Disneyland is crowded that weekend. But the truth is, Disneyland is now super-crowded every week of every month, it's just whether or not you are going to be merely
super-crowded (due to Utah Schools, or Oregon Spelunkers, or Arizona Birdwatchers, or Idaho Bigfoot Hunters, etc.) or if it's going to be
super-duper-crowded (due to Dapper Days, or Gay Days, or the Auto Show, or Columbus Day, etc.)
Don't feel like you picked the wrong weekend. This last weekend was actually less crowded than Gay Days and Dapper Days weekends earlier this fall, both times when Disneyland actually had to close the turnstiles for a bit due to hitting capacity.
The weekend you were there Disneyland didn't hit capacity and the turnstiles never closed. So you picked the right weekend!