I think Annie is still one piece among others of dealing with hidings. You are right - she can't help if all commanders are hidden already. That remains a privilege of Aldebaran (and full Accu).

Another thing that makes her effect less valuable probably is that she might reveal a hidden commander but that commander will not be hit because the targeting is done already when Annie activates. (On the other hand this behavior is one of the main reasons Raksha is still playable.)

Maybe Annie is just an "intermediate solution" that will get obsolete by new commanders with embedded unhide skills but at the moment I like (and - in opposing fleet - fear) her.