From what I've seen, at least in the forums I'm active in, when mods make an edit to a post they usually leave a note in the "reason for editing" field to explain what was edited and why (sometimes citing the particular TOS rule)

So two important things, IMO:

* if an auto-notification feature were implemented, it should include this reason field in the notification email.
* right now the "reason for editing" field is only shown in desktop mode; if you are viewing the FT mobile site it's hidden (and if you edit in mobile mode even if you are editing your own post, the field does not show up for you to populate)

I also think selective editing can serve a purpose, as often when this happens it is in a contentious discussion where posters have useful things to say, but also have personal attacks/jabs thrown in (I'm certainly guilty of this at times). Editing vs. removal in this case allows you to have your say while also keeping the tone civil (and indirectly serves as gentle pressure to be more civil going forward). IMO forums where mods take the time to do this have a warmer and more welcoming overall tone than forums where mods simply delete posts or lock threads.

Having said that, I could see why people might prefer that their posts be removed entirely vs. having their words changed; I think then those people would probably be in favor of this notification feature, so they can proactively become aware of edits to their posts so they can go review them and decide whether they want to just zero out the post content entirely (since you still retain the ability to edit your own post even if a mod has edited it previously)