GW dropped the new Death Guard rule for Disgustingly Resilient, which replaces a 5+++ save with -1 damage.
With the changes to Necron reanimation protocols taken in mind, I think we are seeing a move away from feel no pain rolls to a certain extent. It may be an attempt to have less dice be rolled in a game, or a way for mortal wounds to be more effective.
So how can we predict this would alter our current codex? First, we have Inured to Suffering- an armywide 6+++. Iron Hands kept their 6+++ doctrine, so it may not be automatic that we would lose ours. It seems like saves of 5+++ or greater are being eliminated. If we were to lose this, what could an alternative be? The Forgeworld Wraithseer introduced a new mechanic of counting weapons with AP-1 as AP0. It's not very good, but it's something that I could see being implemented. Even an across the board reduction of one AP on all weapons would be a nerf, but that would come closer to replacing the 1/6 chance of shrugging off a wound for some units. The obvious problem is Wyches in combat wouldn't benefit, nor would Mandrakes or Wracks.
Which brings us to Coven. I am expecting a change here as I can see the frustration in my opponents when I'm rolling 4++ then 6+++ against everything. I think we are going to lose one of the two rolls, somehow. If Wracks get bumped up to 2W each, then I can see a replacement similar to the death guard where Coven may lose one of those rolls for a -1 damage reduction. It's hard to imagine losing an invulnerable save on Wracks and Grotesques, though, without an increase in armor save.
Am I reading too much into the Necron and Death Guard changes?