Yeah, things like tags and the nsfw flag makes sense. It's a useful tool that doesn't hurt anyone, and reduces the hassles involved in removing a post just because there were errors in that surface level stuff.

Now, editing the content, no. Hell no.

The nsfw flag is the more important one tbh.

But, tags allow users to search and sort things (or ideally would, no idea what the actual implementation might be). Having consistent tagging for that purpose is a net plus as a user because if mods can change them, then when you search or sort, there's a higher chance that the results will be consistent. When users pick their own tags and they can't be changed, results get messy unless a mod removes the post, contacts the user, tells them what tag to use, then watches to make sure they use it when they repost/edit.

There's no use for tags other than sorting, searching and filtering. So a mod kinda needs to be able to change them if they're in place at all