The line comes from Halo: Reach, Bungie's 2010 Xbox 360 shooter, where the multiplayer announcer calls out team changes during matches. Phrases like this became familiar to players who spent hours in Slayer and objective modes, hearing the same clipped callouts for kills, flags and player joins. After the game, short announcer clips circulated on soundboards and in gaming edits, detached from actual gameplay. This one survived because its meaning is instantly clear even without context, making it useful for any arrival joke.