Yes and yes? But that wasn't what I was responding too. No wotc staff writes or edits or draws any of it. As far as I know they only set the area and broad guidelines. As far as I know the authors of a given season don't even know what the new adventure is. Just the themes and place they can set them in.
Exactly! The part that matters isn't that WotC staff writes them. It's that they are providing guidelines and overseeing them. Consistency and officialdom. The AL materiel is considered as official.