I think its pretty clear that blizzard pulled the ripcord on BFA not to the extent they did on WOD but clearly it was underperforming and there was no reasonable amount of effort that would fix the issues it had. At that point unlike WOD they at least tried to deliver an ending that at least made some vague sense so they could just move on to shadowlands. Given the delays with the whole unplanned essence system basically it probably would have taken them well into spring/summer to do the ending of BFA correctly and they had no desire to spend that kind of time/money that would also push back shadowlands into next year which would just be throwing good money after bad.