that's classic Korn, they start a project and they never finish it as it wasnt their top priority. they prioritize own music and touring, which is awesome. I love Korn, they are still sooo good live. However, Korn Kovers was planned sometime when Head left the band and they were basically searching what to do and how to continue. They worked some songs out, but I guess they lost interest in the project as it was not as satisfying as they hoped. I think we'll never hear that cover, even though I'd love to hear it. They rarely ever release b-sides or even demos