Fun photos, glad you had a fun time.
it sounds very much the same as the Velo Quebec week long trip called "Le Grand Tour" that my wife and I did a bunch of times. It's usually about 1500-2000 people and also has a fun atmosphere like this.
So, did the sucker in the dunk chair get dunked or not? Wink wink
Yeah the sucker was ME :-) I volunteered haha
here is proof: