It's very disappointing, even if we consider it was a mistake, which I often catch myself doubting, specially because they had to break Lore on the spot by saying Zandalari never had contract with the Fel.
It's even more shocking considering thousands of people attended by paying hundreds of euros plus those who watched via digital ticket who payed around... 40 euros(?) for an event that actively spread misinformation to the masses.
I just cannot wrap my head around it. I would expect a honest mistake to be made by a small company with little resources but not a multi-million dollar company like Blizzard.