However, for those ElvUI users among you who may have been less than diligent about keeping on top of updates - and who can blame you really, I swear ElvUI goes out of date every three days - it seems that instead of the Harlem Shake, you get a message saying all your gold has been donated to the Orgrimmar orphanage. I personally can't confirm this, because for once I did update my UI as soon as it said to. Let us know if you can confirm/deny the orphanage joke!
Big thanks to @Vixsin_LiG5 for bringing the video to our attention, as well as the other commenters who tipped us on ElvUI's goofy prank. Happy April Fools' Day!