Have you looked at the actual change logs?../admin.php?logs/username-change/
This looks like you are viewing the profile tab page, which isn't super clear because it doesn't have the details for each action.
Failing that, you could investigate the admin log for merges.
Finally, there should be a record in the AdminCP on the user account in question that shows the change history.
Have you looked at the actual change logs?../admin.php?logs/username-change/
This looks like you are viewing the profile tab page, which isn't super clear because it doesn't have the details for each action.
For this sample, I'm looking at the final account that accounts were merged into. The 'previous names' field is populated with the accounts that were merged into this record. In this case, the user had created 3 accounts and eventually was detected by Xon's multiple account detection tool. We merged two of the accounts into one, thus generated the record shown above. (There are actually two records here, but I'm just showing one for the example.)
(I've changed the usernames for privacy, but this demonstrates that the record is created and the 'change reason' is the system text entered on the merge)