Okey, I guess Korn might be announced for Greenfield then? But still, I won't 100% rule them out until RfP or Greenfield announce their remaining headliners. Their communication regarding unannounced names/speculations isn't always the best.
This whole GnR/Special day story leaves quite a bad taste. They shouldn't be advertising it under RfP brand or as a bonus day when you have to buy another ticket for it. All the mystery around how many bands/stages will be there that day doesn't help at all and the fact that they changed the dates to 11-15/6 is also very confusing.
But hey, I'm happy for them and hopefully they can sort it out. I won't be there as I couldn't care less about GnR but wish everyone a great show!