Seeing how this dungeon attunement experiment has played out over the past few weeks, there's no question that tuning and pacing are currently missing the mark. Even setting aside item level expectations, when it comes to Normal and Heroic difficulty, most max-level players use the random dungeon queue. Going from picking a random 1 out of 8 dungeons to a random 1 out of 9 or 10 doesn't feel like much of a reward. And early players to unlock them would have faced brutal wait times if they tried to queue for those dungeons specifically, due to the small matchmaking pool. That's of course a far cry from the excitement of earning access to a new Heroic dungeon back in Burning Crusade, for example.
But at the same time, closely tying these dungeons to the zone progression strengthens both sides of the equation. Each dungeon is situated in the context of the overall story arc of the zone (particularly important for Court of Stars), and the zone storyline offers access to meaningful new content as a reward to complement the usual items and Artifact Power.
In the next beta build, both Arcway and Court of Stars will only be available as Mythic dungeons, unlocked at an appropriate point midway through the main Suramar questline. And in hopefully the build after that, you'll see a few extra items spicing up the loot tables of those dungeons as an extra attraction once they're unlocked. Their Normal and Heroic versions were already far less likely to be seen, due to queue mechanics, and this change is aimed at clarifying the role of these dungeons as endgame unlocked content.
It's crucial to remember that while the label "Mythic" may conjure up visions of hardcore raiding and may seem intimidating for those who haven't yet tried them, the main difference between Heroic and Mythic dungeons lies in the expected item level (810 vs. 830ish) and the fact that there is no random matchmaking available for the latter. An organized group of 5 players with experience and gear from Heroic dungeons should find success when venturing into Mythic. Higher levels of Mythic, accessed via Keystones, are where the major challenges lie.
Mythic+ isn't available until raids open. Standard, level 1, mythic is. At least last we heard and that could change.
Correct. Standard Mythic dungeons (zone in, kill stuff, loot stuff, weekly lockout) will be open right away. The only part that won't be there right away is the "Mythic+" Keystone system, since that parallels other endgame progression systems like raiding and the rated PvP season.
Now I will have to wait to continue the Suramar storyline until I'm geared for Mythic?
The Arcway and Court of Stars quests will be optional - they'll become available at the appropriate points in the story, but you'll be able to continue the main quest campaign even if you don't finish them. The intent is for unlocking Suramar's dungeons to be a reward for progressing that far in the questline, not to block further quest progress until they are completed.