That is of course always an option. I said "any time", and 9:30 am is certainly a time. But what about holding it at, say, 11 am, or 12 pm, or some other time

That is of course always an option. I said "any time", and 9:30 am is certainly a time. But what about holding it at, say, 11 am, or 12 pm, or some other time that's later in the day and doesn't conflict with the lunch period? Then perhaps it would be OK for everybody, early risers and late risers alike. It's not like the day absolutely has to start with a meeting. (If I wanted to punish people that like to get up early, I'd suggest holding it at 6 pm or something. That ought to cause maximum annoyance to people that are good at getting up early: not so late that it's an unreasonable demand, any more than 9:30 am is, but still late enough that it's probably going to mess about with how you'd naturally structure your work day.)