Your point exactly illustrates how Raiding is the focus, not just part of the focus. Arena testing has been non-viable due to trinkets blowing everything up until just days before the expansion release.
There’s words and actions dually contributing to the relationship with the end client / user; and the high end mythic raiders are not the entirety of the player base, though they influence it. I would find to to be more effective to speak on balance / temporal balancing and systems, instead of speak on mythic raiding anecdotes to use as a descriptive crutch of balance and systems writ large
Loosely, but the patching, and communication are both centralized on raid optimization / balancing. See point above, to Gethard, for further detail.