I have never seen one, but I look forward to it....
I look forward to any flagship additions really. I don't really like the reduced number; it just leads to camping, rather than a natural sailing route. I don't mind camping off a coast when I'm working on Cannon, but otherwise I like to sail...or rather "outsail the enemy." Usually I like to do a bit of both Cannon and Sailing, so I need ships that can take a pounding or they're ready board too soon.
Black Harbinger flagships sure would be fun, and it'd be even nicer if they added Navy Predator & EITC Corsair flagships, plus Navy Dreadnaught & Monarch, and EITC Warlord & Ogre.