When I was beginning to wake up, but hadn't left yet, we blew out the Regional thingy, I think it was called a District Convention in those days, nobody noticed we were not there ! I thought my J.W family might notice, but thankfully, no.
We never attended another Convention of any kind, having got away with that one, then we left just over a year later.
I remember being a bit careful in conversation with a few J.W's shortly after each Convention, but they soon forgot about it.
With the attendance thing mentioned in the O.P and other Posts, I don't remember it being particularly well attended every day, maybe Sunday, but I think a lot skipped going, like me, for at least some of the days.