World of Warcraft User Interface Add-On Development Policy (2018)
1) Add-ons must be free of charge.
All add-ons must be distributed free of charge. Developers may not create “premium” versions of add-ons with additional for-pay features, charge money to download an add-on, charge for services related to the add-on, or otherwise require some form of monetary compensation to download or access an add-on.
Offering NPC data to only those that pay clearly falls under “services related to the add-on”. Importing that data to make the addon usable could also be considered a “premium” version of that addon.
People have already shared the NPC data on pastebin, and Blizzard is very likely to take issue with this given the popularity and impact of this one addon. I expect after Blizzard steps in, the man child in question will either re-add the data or walk away from the addon, at which point someone else in the community will step in to replace it.