I see the point regarding turning other users’ post into wikis, and agree that it would be a feature request here.
I guess I find it rather counterintuitive that they may edit others’ posts freely, while being unable to “edit all their metadta”, e.g. turn them into wikis.
This however creates a particularly weird edge case: Usually, the post edit time limit does not concern category moderators for their own posts, as they may edit other users’ posts indefinitely.
However, it suddenly comes into play when they would like to turn them into Wikis after the fact, which seems a bit inconsistent.