I'm pretty excited for this. I love these old flashbacks to older content, like how they included Ulduar and Karazhan in the intro scenarios. Brings back a lot of fond memories and makes the world seem like a more coherent place, as opposed to just new things popping up all the time and being forgotten forever a month after being discovered, even when these things are prisons for extra-planar supermegagodlike beings with dudes running around who can literally just rewrite the whole world upon whim.
Hoping it'll be Mythic+ only though. Would feel pretty stupid to have it in LFD.