Its a book https://whenitsready.com/wowdiary/ originally sold as a kickstarter by one of the original Blizzard mappers made from notes they wrote while working on original wow. They did some AMAs[1][2] with other wow developers that sort of touch on some of the topics discussed here.
[1] https://www.reddit.com/r/wow/comments/9huows/ama_former_wow_...
[2] https://www.reddit.com/r/classicwow/comments/9fb2bo/john_sta...