For example, the following situation may happen: the moderator approves the post of a specific user 1 hour after it was posted, but 50 new posts from other users (who don't need a pre-approval) appear in the topic during this hour. In this case, the moderator will approve an 'old' post that will be lost on the previous pages, and nobody will really read this post.
I think it would be reasonable to automatically change the date/time of the original post to the date/time of approval, so that it appears as a new post.
I've also found a similar suggestion posted previously:
javiexin wrote: ↑Thu Feb 02, 2017 3:19 pm if you have an "unapproved" post, and before it gets approved, there are other posts in the same topic (that might not need approval), if someone visits the topic, the "unapproved" post will show as read when approved, and it should not. Besides, it is listed in "publication" order, but it should probably be listed in "approval" order (to be consistent to when this post was VISIBLE to everyone with the right permissions).