This is still broken in two different ways. First, if a user is deleted (BitBucket server), that user's contribution history becomes unavailable immediately (since the user no longer has a profile), unlike other Atlassian tools where the user can be disabled. In an enterprise environment it's quite valuable to see all of what someone did after they're gone!
Second, the failure mode is an 500 (internal error).
https://(bitbucket server url)/plugins/servlet/user-contributions/(deleted-user-name)
...produces a 500 error ("Please see your system administrator") instead of a reasonable message.