Yeah - we were there too - it was really cool!
I think that to understand the difference between an organised parade and a "not official parade", one needs to get into the Swiss mindset.
As the websites said, and I said....it is just "wandering about" - the fact that when the Swiss wander, they all wander in the same direction at about the same time, doesn't mean that its "organised"

. For "organised", they need badges and start times and security on the route, and permits and permission to join the parade. Yesterday was just anybody show up, dress up, put your kids in a wheel barrow or trolley (what do they do with these buggy things for the rest of the year

) and join the throng. That's why I was saying, just show up.
Today's bash will be much more grand with the full parade and procession - certainly worth a look