Based on the feedback in T180080#3748420, instead of getting all the pages a user has edited, we should take the revisions that are being displayed and query the API to see if the page has ever been edited by the other user. This may result in more requests, the requests will be faster since they can be executed in parallel.
As an alternative to doing this we could T180546: Create an API for Interaction Timeline and then this task can be implementing an endpoint to get the revisions.