When a user makes an edit, and that edit causes edit conflict for another user, the former user should be notified about that.
This can help solve at least two rather social issues:
- Raise awareness for users who tend to make many small, likely maintenance related edits, that their edits are actually causing problems for other users. E.g. it would make sense for them to wait some time after a new article was created to let the creator to finish layouting it rather than race there to fix it themselves right away. If we show editors that their edits disturb someone else's process of editing they might change their editing style further on (like using section editing more, waiting for some time if the page is created in one edit etc.)
- Another thing is that some users in case of edit conflicts tend to just replace any changes made before them with their own version of page content. This is definitely a bad behaviour but it might end up being unnoticed. If the faster edit's author gets a notification, then he can go and check whether the final revision still contains their changes. Basically it is the same kind of notification as the one for revert/cancellation of the stuff.