The missions they released have nothing in common with what was discussed. PvE was meant to have persistent hero levelling, skill trees, and a proper story. What they eventually released wasn't far off what would've been a seasonal event game mode in the past, in addition to being laughably expensive and horribly broken.
> Also, you mention unpopular balance patches, but "Blizzard sucks at balancing" has been a complaint since the early days of OW1 :P I remember when the first Mercy rework dropped... and the Bastion rework... and everything about Brigitte...
The OW2 changes went beyond a broken hero. They made fundamental changes to the way the game is played with the reduction in team size and changes to tanks.