Introduction
The Flag system is a useful tool that can be used to take down post that are Spam, Inappropriate, or Unnecessary.
How It can be Stressful sometimes
The Flag system can be a little bit stressful while deleting posts. When deleting a post it will take 1 hour to delete but it will stop if it is flagged. When some one is deleting a post they have probably resized that there message was spammed, unnecessary, or inappropriate. When something is flagged it can also be a wrong flagged so the moderation team might have to go through a bunch of spammed flagged messages.
My fix
Make it where when you delete a message that you think is inappropriate, spam, or unnecessary it should go away. Make, It So you can’t flag a deleted post. Make a system where the community can decided where if the post is fair to flag or not and they should be a certain role so this can not be exploited for the use of the person flagging it.
If this were the case you could pretty much post anything you like, no matter how inappropriate, and then just delete it to avoid it getting flagged and moderated. I think that’s why the system is as it is right now.
Besides what is said above, I don’t think this issue is that common. If someone flags a post that you delete, it will be moderated at some point… so what? I can’t see any reason that you would need your post to not be moderated other than if you are purposely trying to break the rules.
In addition, this is not currently possible with Discourse. I can guarantee you that this feature would not be implemented on any forum, making it a useless waste of time for whoever tried to make this a plugin.
Yes at @BanTech said, rulebreakers can get away, but also:
In a new topic, if someone can instantly delete their reply, it’ll break the flow of the conversation much more than if people were able to know for some time that it was deleted.
Plus, I don’t get your point that flaggers can use it to their advantage. It’s not that easy to hide a post unless a certain threshold of people do it (which is unclear for a reason). Meaning, there isn’t a big possibility where a huge group of people go around flagging the same posts. Even if that did happen, it would still be made “unflagged” by the mod team for incorrectly flagging. Speaking of that, incorrectly flagging is against the rules I believe.