I was editing an answer and wanted to say "we can also write this if [author name] agrees" but noticed that the author name was written nowhere on the post edit page interface. I had to open a new tab in the previous page to find the author's name. Eventually I just wrote "the author" which is easier, but I still think it may be nice extra info to provide while editing a question/answer.
When there are revisions, you can open the dropdown, and the author of the first revision is the original author indeed, but otherwise the author name is not displayed at all. It could simply be written at the top before Question title for a question or after "Answer by" for answers. Or it could be shown at the bottom-right along the avatar as on the main view of a question + answers.