The following is as it relates to a video game, playable for Xbox and PC. "Woot Woot Woot" is the sound that the covenant elites make as they charge you in Halo CE. (combat evolved) Some people think that all of the aliens in the game speak backwards. That would make them say a version of GO GO GO.
Could be related to wOOt. From D&D meaning Great,(wow) Loot!