As a follow on from edit history, author attribution tracking and drag and drop, provide an indication on the quoting page of whether a part of a quoted page (that has been excerpted and put into the quoting page) has been changed.

A page author borrowing / reusing material from another page would find it helpful to know if that material has been changed, and be free to decide whether to reflect that change in the quoting page. Probably not MVP.

This doesn’t necessarily need to be separate functionality, because one page could look at another to see if a quoted section has been changed or not. The question is how notification of changes is managed. The quoting page could do an explicit check for each of the passages that are quoted, and if the source passage has changed (not just the whole quoted page) then that passage can be marked in some way. The quoting page owner can then decide whether to update the passage in line with the updating in the quoted page, or not. Either way, the status of the quoted passage can be seen (directly or indirectly) by the reader of the quoting page.

It’s perhaps not vital, and I know of no known implementations of exactly this, though Fedwiki does something related.