The parent ticket for this one indicates, that the RevisionRecordInserted hook is run for all the historical revisions of the page when it's undeleted. Since that hook is used to create revision-create events for Event-Platform used by ChangeProp and Analytics, this is not a desirable behavior - all the Parsoid HTML and dependent content types get re-rendered, the analytics edit history database gets updated etc etc.
For pages with a lot of history, this creates significant and completely unnecessary load. So it could be cool if the hook provided info on why exactly the revision was created - whether it's due to page undeletion, a redirect left on a page move or a normal edit, however right now I don't see a way to figure that out from the hook. That way Event-Platform could either filter the unnesessary events or indicate the reason of the event creation to the consumers.