Captaincy rebalence reward

It should do. As per the news post:

You will automatically be awarded this exclusive reward if you have earned Class 50 in any individual Pirate Milestone from The Gold Seeker, The Voyager, The Emissary, The Hunter, The Feared, The Guardian or The Servant, with the exception of the following specific Milestones: Nautical Miles Sailed, Days at Sea, Provisions Cooked, Provisions Eaten and Cannons Fired.

They used the words "specific Milestones", which would mean any Pirate Milestones in the categories listed except for the ones mentioned will count.

Milestones in The Ill-Fated, The Rogue, and The Captain, won't count either.

I came to the forums to ask this exact question. It seems like they made exceptions for all the other naturally easy ones and that maybe this one will not actually be counted.

As far as we know it does, but rare may end up seeing it as an oversight so it may be worth grinding out something else that looks easy if you really want the table just to be on the safe side.