It's baffling to see people already complaining the raid is overtuned simply because Star Augur lasted two days. The last bosses may be unkillable this week for regular mythic guilds, but so what? There is nothing wrong with bosses requiring the grinding of prior bosses for a few lockouts before people have enough gear to move past them.
Do people not realize we only have actual progression on WoW once every few months? Why is it a problem for it to last longer than a week?
Let me give you some perspective. The Burning Crusade launched on 16 January 2007. Tempest Keep as a raid (after attunements) was available at launch. Nihilum got the world first kill of Kael'thas on 25 May 2007, after over four months. The next tier, Black Temple, was released on 22 May 2007. That's right, Kael'thas wasn't killed until after the start of the next tier.
That may be overkill, but it shows the world won't end if the hardest difficulty mode of a raid lasts a few weeks. It definitely shows a boss that lasts two days isn't overtuned.