I think you and Dan (Below me) are a little mistaken. He was referring to the Blood Elf leaders, not every factions' leaders. The Blood Elf leaders he is referring to are Lor'themar Theron, Grand Magister Rommath, and Halduron Brightwing. You could also consider Lady Liadrin as one of the leaders.

He said that Priests don't have a leader that represents them. Lor'themar and Brightwing are rangers who represent Hunters and possibly Rogues, Rommath is a Mage who represents Magi and most likely Warlocks, and Lady Liadrin is a Paladin who represents Paladins. Priests are left all by themselves without someone to properly represent the in their government.

It could be argued by some uninformed that Liadrin could be representing the Priests, but she and all the Blood Knights, former to the events following after Kael'thas Sunstrider kidnapped M'uru, got their ability to control the Light from the energies emanating from M'uru while the Priests still got their power willingly given up by The Light, making an possibility of the two classes being linked implausible.