Board Thread:General Discussion/@comment-70.44.241.171-20180712133652/@comment-207.189.46.149-20180802035200

You would have to ask the admin. If I had to guess, I would say they prefer it for neatness purposes. From your description, it sounds like you were the next user to comment after your own comment. Having consecutive comments might make it look like two different users. So the admin might prefer you edit the previous one so that it is clear it is the same user.