There's lots that have support channels though for programming libraries, for games, etc and having all of that content locked away can be really damaging.
One of the interesting things I've noticed is when a community for a more niche game / programming library joins Answer Overflow, they often shoot up to being top performers on the site which is great to see.
Along with that, not all channels are indexed, mainly just help channels. What's nice with this is it keeps that cozy feeling of a private place to talk, while helping more people find a community they will enjoy and keeping information accessible.
Long term, I'd like to implement forms of anti-abuse tools for communities to use so they can understand what the types of people who join their server from Answer Overflow are like. For example, if it turns out that 90% of the people who join are abusive, then it'd make sense for them to turn off indexing.
You could possibly make the argument that for the long term health of some communities, having indexed content helps to keep the community active