The reason given is: Unneeded. You can debate this at the talk page. If nobody objects, go ahead and make the proposed changes.
The Black Night and Nigel's Ninja outfits are clothing sets available for Battlefunds. Since it first appeared as a battlefunds monthly exclusive, they reappeared and featured for a long while as a hot deals bundle. It is actually the second ninja outfit of the Royals.
The bundle was released September 2009. [dead link]
Ninja history including the clothing changes and martial art comparison: http://www.battlefieldheroes.com/forum/showthread.php?tid=66057 [dead link]
It was resold in 28th November 2011 within the Heroes of the Rising Sun theme.