I am only part in agreement with you. But mostly disagreement.
Legion Timewalking, Mage Tower and M+ are all very welcome additions to the game. Timewalking has been a thing for some time now, so it’s natural for them to progress into Legion TW as per schedule.
I would actually like to see Time Walking further implemented into the game. How, that’s not for me to decide, but I don’t think we should be waiting 3 weeks for the next TW event, it’ should be permanently on.
Having said that. You said:
This is indeed true, and Blizzard has failed to deliver a quality product on this occasion.