You actually can already do this; you have to manually figure out the editor's username, rather than having it "pop up" for you, but if you guess correctly the editor will be pinged. See meta FAQ here:

Who can be notified with this feature?
...

• Any user who has edited the post (does not include pending or rejected edit suggestions).
  ...
  Why do some names not appear in the auto-complete box?
  ...
  Additionally, only users who have commented on the post are ever populated into the list. Editors and other users from the post's history will never appear there, even if they are able to be notified by typing manually.

I haven't tried it myself, but other people have, and they assure me it works.

You actually can already do this; you have to manually figure out the editor's username, rather than having it "pop up" for you, but if you guess correctly the editor will be pinged. See meta FAQ here:

Who can be notified with this feature?
...

• Any user who has edited the post (does not include pending or rejected edit suggestions).
  ...
  Why do some names not appear in the auto-complete box?
  ...
  Additionally, only users who have commented on the post are ever populated into the list. Editors and other users from the post's history will never appear there, even if they are able to be notified by typing manually.

I have now tried it myself, so I can attest that it works.

I think you actually can already do this; you have to manually figure out the editor's username, rather than having it "pop up" for you, but if you guess correctly the editor will be pinged. See meta FAQ here:

Who can be notified with this feature?
...

• Any user who has edited the post (does not include pending or rejected edit suggestions).
  ...
  Why do some names not appear in the auto-complete box?
  ...
  Additionally, only users who have commented on the post are ever populated into the list. Editors and other users from the post's history will never appear there, even if they are able to be notified by typing manually.

I haven't tried it myself so I can't promise it works. (But if some third party wants to edit this post I'll try to @ you and we can find out ;-).)

You actually can already do this; you have to manually figure out the editor's username, rather than having it "pop up" for you, but if you guess correctly the editor will be pinged. See meta FAQ here:

Who can be notified with this feature?
...

• Any user who has edited the post (does not include pending or rejected edit suggestions).
  ...
  Why do some names not appear in the auto-complete box?
  ...
  Additionally, only users who have commented on the post are ever populated into the list. Editors and other users from the post's history will never appear there, even if they are able to be notified by typing manually.

I haven't tried it myself, but other people have, and they assure me it works.