I think it probably makes sense to host similarly moderated content together.

programming content being grouped together makes sense because it’s moderated to a similar extent between languages and communities.

For example discussions/posts on rust programming and porn are moderated very differently, so they should be on different instances.

I think we agree, and I didn’t know “moderated similarly” was referring to admin policy. Basically you want the people at the top to be generally aligned with the views of the community