Heard about this yesterday.
I've been courting the notion of putting a 5.7 Hemi in my 2015 JKU. It's a spendy upgrade to get an aftermarket 4x4 shop to do it, around $25k. But trading in my Jeep with all its aftermarket farkles, for a JL that doesn't have them and having to re-obtain them all for a slightly different design, in order to get the 6.4, and finding out where I stand with a $60,000 vehicle, may make the aftermarket upgrade make more sense.