CID Le MDC appears to be one of many short reaction sounds that spread through reposts, soundboards and meme edits rather than through a widely documented original source. When a clip like this catches on, people keep reusing the same short phrase because it is easy to recognize, easy to time with cuts, and effective in low-context jokes. Its staying power comes from that quick, quotable format, similar to other short reaction sounds such as bruh that work instantly in edits.