This sound is a generic celebratory vocal effect rather than a clip with a clearly documented origin. Short "yay" sounds have been widely used across soundboards, reaction edits and mobile videos for years because they communicate success instantly without needing context. Creators keep using them in memes and casual edits since the meaning is obvious, the timing is easy to hit, and the tone stays light. It often fills the same role as a quick ding sound effect when a visual moment needs a fast reward cue.