What happens to checked out items when an orphaned user gets removed?

Question

So we are in the process of cleaning up old orphaned users who are getting sent email alerts. Is there any downside to removing these orphaned users from a site?

What happens to any files checked out/created by that user? Are there any issues when migrating to different versions of SharePoint?

Answer 1

Checked out files will remain checked out to that user. Created By/Modified By will remain until you migrate that content via a content migration tool, such as Sharegate. Otherwise if you perform database attach upgrades, the data will remain consistent.