Why are mythics in the Suramar questline if they are not required?

[paladin62]

Why put them in there if they have NOTHING to do with getting reputation or completing the area?

[ZG Support 1]

They are required for completing Suramar Loremaster.

[Cartman]

The Good Suramaritan achievement does not require doing mythic dungeons.
The "A Growing Crysis" part requires to kill Xavius in the Emerald Nightmare raid (LFR is sufficient).