Would love to create a nice animation for it 
EDIT: Opened a PR
https://github.com/discourse/discourse/pull/7356
Problem is that even after turning the “saving” into an animation, there can still be an error like “Edit Conflict” or “Drafts Offline” which then would still be displayed as text and thus require more width.
An Idea I have on this one would be to show a cross instead of a check if there is an error and show the error message as a tooltip if the user hovers the cross.