I just ran into this. We have a small community which uses discourse as a mailing list which had two active threads. Someone replied to thread B with a comment intended for thread A, which had drifted off to a new topic ©. By the time the problem was realized, there were a bunch of comments in thread B about topic C.
So I created a new thread for topic C, and moved all the posts from B, then moved all the posts from A also. But now I have all the later posts from B after the earlier posts from A, which is really confusing.
Is there any way to reset or change an individual posts time? I would be willing to manually set the order of each message if that was possible.