Maybe it's just that I personally was raised with zero attendance at anything remotely that structured, but it's hard for me to imagine kids sitting through all those highly abstract stories, many of which rely on lots of background concepts, and being anything but bored stiff (and probably annoyed). Am I wrong?

(shrugs) You're not wrong, but I'm not sure you're right either.

In my own case, growing up as an Orthodox Jew involved sitting through lots of highly abstract ritual observances that relied on lots of background concepts (and frequently being bored stiff and annoyed). And if a rationalist group is only as successful at retaining the involvement of parents and their kids as Orthodox Judaism is, dayenu. (Which is to say: that would be sufficient.)

More generally, I suspect that it's perfectly possible to involve kids in something that structured, it just requires giving the kids roles they can engage with in that structure.

A comment I made in the introduction article:

There are people in the NYC community who expect to have kids soon, and friends in San Francisco with kids who might potentially come to one in the future.

This whole experience was inspired by my family's Christmas Eve celebration, which was inherently designed for children. I customized it for the people who make up our community now, but will definitely be revising things as kids become part of the equation.

This may well involve splitting off into multiple events that kids don't participate in. (For example, we might have the "fun" part of the evening end with some activity for kids, and then they go to bed, and then older people do the more serious sections). How exactly to handle it depends on how many kids are coming, how old, etc. We'll cross the bridges when we come to them, but yeah, they're coming.

More generally, each community that wants this will need to customize it for their own needs. Daenerys' event in Ohio didn't end up having singing or litanies at all, instead being built around custom vows and affirmations.