I think any event that celebrates a bygone era is always fun. Examples of older bikes, or whatever the item, is like touring a museum.
But it tends to be generational, and participation tends to decline as each generation moves on.
In the late 80’s/early 90’s I was involved in classic cars. It was a time when every week there was a cruise night somewhere; 50’s music, old cars (mostly hot rodded), and a lot of fun comparing and reminiscing. Every year, there was the Great Labor Day Cruise with a 1000 cars. It’s all gone, or nearly all gone.
For these events to continue, they do need to move forward. I can support a pecking order and special consideration given to those bikes that embrace the original criteria. I have not participated in one, but the start should be era driven.
John