So, I've been out, but I'm gonna give my two cents on the supposed meta-gamer. Personally I think it would be really cool to have someone with that power. As long as there character's goal wasn't to out people, but sort of just realized it, then I'd be totally cool with it. Shoot, he could even be trying to hide the fact that he knows who everyone is. Now, if he just wanted to declare everyone to the world, that would be a killjoy, but if my character is trying to stay secret, and he's the only one that knows, but my character doesn't know he knows, then my character wouldn't care. Who cares if he knows? It doesn't matter. So, really it depends on the character more than the power, but I think it could be really cool. That's just my take. 

P.S. [@candlelitcraft] 
You wouldn't need that power and it still might work on my char.