I have participated in 3 WNBRs. 1 in Austin (2012) and 2 this year, here in Houston. The Austin ride was just a ride to the Capital, then return through a different route. Excellent pre & post parties along with some celebration at the Capital. Otherwise simply riding through the streets.
The 2 Houston rides carried us to specific locations to pay respect at sites of bicycle fatalities. We stopped at several locations along the way to celebrate and maybe'grab a beer'. We did have a bit of a pre-party, but nothing at the end as it was after 1am.
I encountered several along the way that either joined us on the spot or promised to be at the next ride.
We stopped at several places along the 2 rides in Houston. (3 - 4 each). All were prearranged with management, all were regular 'no shirt, no shirt, no service' craft breweries or eclectic bars. All but one accepted us nude. The one proved to be a prank on a junior manager. She was not amused when dozens of nudes walked through the door of her bar. The owner had been contacted and said 'no worries, full support for our cause.'. He either intentionally, or not, failed to inform the manager on duty. She refused to serve us even after we put something on.
The last stop on the last ride was downtown, right on main street, just after midnight, on Saturday. Traffic was at a standstill, and finding bicycle parking was a chore. The only time I was ever photographed more was streaking in the 70's. We covered before entering, but the staff would have none of it, so we stripped off our textiles and socialized with the staff and customers.
Just as the rides in Austin and Houston we're different, rides elsewhere have thier own character. One of the women on our rides in Houston has ridden in Portland, one of the largest rides out there. She spoke highly of both rides. There are a lot of details on various rides, so pick one that fits your expectations.