Considering that the 5.4 LFR will most likely be ilvl 526-528, and require 500 ilvl, I don't see that really being a problem.
What I HOPE will happen- LFR, 526 ilvl. Flex mode, 534 ilvl. Normal, 547 ilvl. Heroic, 560 ilvl. With, of course, Heroic Bloodsoaked Upgraded being 576 ilvl. Will see I guess.