Sounds like this became popular as editors looked for a recognisable way to mark a job finished without recording their own voiceover. The reference to MP3, WMA and OGG points to the era of desktop audio converters and ripping software, when those three formats appeared together in almost every export menu. Online, the clip survives as a joke about old PC workflows, used ironically for downloads, renders and edits that are finally complete after a long wait.