I don't think this is particularly useful. There are just a few places that allow comments and pings. If you would allow pinging users from the revision history, you need a way to flag them, review them, etc. That seems an awful lot of work for something not very frequently used. A comment on the post is the most appropriate since it is A) visible, and B) uses existing flows for flagging, etc.

I do agree on the (possible duplicate) Decision on rejected edits should be displayed as a notification to the editor, which states that there should be feedback about the reviewing process. I just don't think your proposal is the best solution for this.

I don't think this is particularly useful. There are just a few places that allow comments and pings. If you would allow pinging users from the revision history, you need a way to flag them, review them, etc. That seems an awful lot of work for something not very frequently used. A comment on the post is the most appropriate since it is A) visible, and B) uses existing flows for flagging, etc.

I do agree on the (possible duplicate) Decision on rejected edits should be displayed as a notification to the editor, which states that there should be feedback about the reviewing process. I just don't think your proposal is the best solution for this.