We ordered our 2018 Max FX4 in early January and in March my twin brother picked used 2017 SWB 4x2 Limited (Replacing his wife's ~2007 SWB 4x2 Limited). We spent over $30k more than him. Why'd we choose differently? Is there any one feature on the 2018s that's worth the $30k premium*? No. But there's a bunch of stuff that's worth a little bit more and which really would be nice to have. Add them all up and are they worth $30k? Depends on whether or not you have the $30k.
Or put another way, you can save $30k, but what do you have to give up? Locking rear differential, 2" of ground clearance, skid plates, 10speed transmission (we have a 6000lb GVWR travel trailer), 50 ft-lbs of torque, panoramic sunroof, tip and slide seats*, auto-cruise control with stop and start, transmission temperature monitor, terrain control system from the raptor, a nicer interior, a truck that doesn't already look dated (even if it doesn't look as "tough"), etc, etc.
Sure some of that can be remedied via aftermarket parts, but then you've got to source them and find time to install them (or pay even more money to have them installed) and maybe you just voided the warranty with that lift and, and, and, well, now you didn't really save the full $30k, you put yourself through a whole bunch of unnecessary hassles, and you still didn't get everything you wanted.
Additionally, we both ended up with Expeditions, but we were cross shopping very different vehicles. He was cross shopping 3rd and 4th gen Expeditions with the Armada as his dark horse candidate. I was cross shopping the Z71 Suburban**, the Yukon XL Denali and the new Discovery.
With this in mind, I strongly suspect the returning Expedition shoppers are going with the Gen 3 leftovers while the Gen 4 is poaching a bunch of people who would've otherwise bought a GLS, Disco, or Denali.
*Ok. Yes, the tip and slide seats are probably worth the $30k.
**6000lb towing capacity with the off road package? Really? And the skid plates are crap!