during the 'beta' phase

Oh man, that was a painful experience. haha! It was pretty rough at the beginning. Things did improve quite a lot over time.

To this day it would be hard to convince me that the WOW team did not straight up copy

This was a huge subject of conversation in-game on AO back in the day. Everyone was trying to copy the good parts of AO and do them better. I don't know if anyone ever succeeded.

The game had plenty of good and bad points for sure, but I don't think anyone could argue that it wasn't a benchmark that other MMOs of the time measured themselves by, or at least took a lot of inspiration from.