It does. Want the world boss artefact appearance?
Fuck you, scrub, only raiders deserve that.
Want the Glory dungeon artefact appearance?
Fuck you, scrub, only raiders deserve that.
Those non-raiding appearances shouldn't be locked behind raiding.
Best way would be for the questchain to be doable in LFR, but for the first appearance to drop off normal or higher Gul'dan for players who'd already done the questchain.