Using Kentico Xperience's Object Locking is very important when you have multiple people in a system, but when someone forgets to check objects back in, it can become a problem. We've seen many clients lose work because they chose to click the "Undo Checkout" button to get back in (you really never want to do that). If someone has good changes/updates, you will want them to check it back in.
Many times a user will click "check out", so they can check the values of a web part, but then they forget to undo the check out. A few weeks later, this can lead to confusion. Were they in the middle of an update? Was it unintentional?
This check reviews all the items that are checked out, and lets you know if anything has been checked out for a while. If someone has something checked out longer that the default value (7 days), then it is likely checked out accidentally. This can lead to issues in the future. So, while the changes are still relatively fresh in the person's head, you may want to ask them to either check in their changes (or undo if it was truly unintentional).
Having this check turned on can encourage good habits of timely check-ins.