Hmm, as someone who's been around those communities, largely on reddit, I got the impression that childlessness was neither a major concern of theirs nor a contributor to their worldview.

The fixation was on their lack of romantic connection and sexual experience, hence the title of involuntarily celibate (and not involuntary childless or socially infertile, which are actual terms that I've seen used by the media).

The memes such as "I can't breed" were more a play on words than actual concern at the possibility of being unable to have children.

If anything, it often seemed like they tended toward antinatalist or doomer-esque mindsets. Some specifically said that they'd never have children because they wouldn't want to burden a child with, what they self described as, their 'subhuman genes'.

The media discourse around them never seems to mention childlessness as a factor, either.