(a) You don’t explain why, in your opinion, you see it as a very poor basis to form a community ...
If someone has a problem with their mother/sister/aunty banging on about them starting a family, that's a relationship problem.
If someone has a problem with every other woman in their workplace taking maternity leave, that's a workplace problem.
If someone's worried about having no descendants to leave their worldly possessions to, that's an inheritance problem.
If someone wants to find the cheapest flights in mid-July on a plane that'll have no children on it, that's a Travel problem.
Just because someone has children doesn't mean that they're not well qualified to give advice on how to deal with any of those child-free situations.
So on the one hand, we have the proposal to make this forum inclusive and touching several different topics (all of which are catered for elsewhere on the site); and on the other, it's intended to be a place for members whose lives are overwhelmingly infused with their deliberate decision to not have children. Those two states are incompatible.
Out of curiosity, I've just had a look at my own circle - 4 out of my 5 most recent WhatsApp chats are with childless people, 3 out of my 5 most recent texts are to people with no children; and 4 out of 7 individuals that I follow on YouTube are child-free (6 if you include those with grown-up children). I have three 40-50yo female cousins (in rural Ireland) and one male who have no children and it's never been considered abnormal.
Perhaps it would be useful to propose a handful of likely thread topics in this discussion to see what level of engagement could be expected?