Something like 8 million people bought Shadowlands within the first few months. There was no lack of initial hype.
The truth is, people were mostly fine with 9.0… except we hit the 4 month mark and there was no 9.1 in sight. And then another month went by, and another month went by, and you only need to look at Bellular’s analysis of engagement analytics to see that people just got bored of 9.0. And 9.1 barely did anything to turn the losses around because it was a bare-bones patch all things considered. We were something 15 or 16 months into the expansion before the expansion got its first meaty update. Of course the expansion was doomed.
Blizzard themselves acknowledge this, that one of their biggest aims in Dragonflight is to improve their content pipeline.
Time will tell. We cannot say DF won’t fail until we see them deliver post-launch content.