Not small updates, but rather specialized updates.
Instead of a major patch needing a zone, raid, cosmetics, story, etc. You could have one patch that is just a load of story stuff, then later a patch that is just a meaty raid, then another with a big zone filled with world quests and such.
I could be wrong, but I think this would have meant a smoother stream of content as each individual piece doesn't necessarily need to be combined with others. The team responsible for a new raid doesn't need to necessarily concern itself with whether a new zone is ready for instance.
Of course, with how WoW is currently structured this would probably just end up dividing a larger patch into smaller individual patches, but if WoW had managed to break away from the structures narrative and instead have smaller more localized threats then I think it would have been ideal.
But it's not like this would be likely to happen regardless, so it's kind of s moot point. It would require restructuring the entire dev team, both writers and coders.