The problem with the gear is not merely "higher ilvl for each tier", as it was before Cataclysm. The problems with the curve going hyperbolic occurred because they implemented multiple ilvls of gear *within each raid tier*, so the heroic raiders would feel they were getting better rewards than normals, and normals would feel they were getting better rewards than LFRs. As in, you didn't get multiple sets of ilvls out of Molten Core, or Blackwing Lair, or AQ40, or Naxx (original), or Karazhan, etc, etc.
They will continue to have the same problem, unless they go back to a single ilvl set for everyone, regardless of raid type. And we all know that they won't do that because the whine would be heard around the world.
If you want to see this, then look at a graph where the ilvls are broken out by raid type. You will see that it is the normal and heroic gear that's gone hyperbolic. The LFR gear has stayed relatively on a steady uphill climb from Classic gear. To describe it a different way, what you are getting out of SoO LFR is what you "would" have gotten from Normal SoO, and what you are getting out of SoO Flex is what you "would" have gotten from SoO Heroic, if LFR and Flex had never been added in there forcing the top end numbers to be higher... in a world where only Normal and Heroic raids exist. If this were still the Classic model and only Normal mode existed, then the LFR ilvl would be the top end. (You have to back that out through when LFR was added to the game in Cata.)
Removing one of the current 4 ilvls (LFR, Flex, Normal, Heroic) next xpac is going to help some, because it allows them to set the Heroic top end ilvl lower than if they had to pad it for 4 ilvls instead of 3, but the borked up curve is still going to be there. In a few expansions they will have this same problem again.