I think that Blizzard never learns, because when a new expansion comes out, he becomes like a mad scientist who takes out and adds things to the game without meaning, and without caring if it was for good or for bad, and then withdraws it in the next expansion without caring nothing if it was good or bad what he did.
in the end what else does To return old skills, because it is the same as what he said about GCD’s, nothing happened, that he will not see more farmde azerite, but there is still more farmer and it is not known what kind of another farm will be in 8.3.
Speaking of old skills, that was also in BfA but I only return few as fortitude of the Fortitude priests and some aura of the paladins or your warcry of the warriors, but I lack more as their Gift of the Wild of the Druid that was the most necessary.
What Blizzcon showed was not as much as the versatility of precense in the DK as in WotLK, some few skills for the DH but of Legion, totems of the shamans like Totem tremor and other auras of the warlocks.
And after that there is still more, as it is not necessary to include all the Vanilla due to the arrival of new classes and races (DH, Dk, Monk) or Nightborne elfs or Darkiron dwarfs.
Which to say that he learned something from the Classic, for 15 years and changes of new organizers such as also the so-called brain drain, I think he learned nothing for this long time.