The relevant parts of the policy below
Originally Posted by Blizzard Entertainment
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.
2) Add-on code must be completely visible.
The programming code of an add-on must in no way be hidden or obfuscated, and must be freely accessible to and viewable by the general public.
4) Add-ons may not include advertisements.
Add-ons may not be used to advertise any goods or services.
5) Add-ons may not solicit donations.
Add-ons may not include requests for donations. We recognize the immense amount of effort and resources that go into developing an add-on; however, such requests should be limited to the add-on website or distribution site and should not appear in the game.
Original here:
https://us.battle.net/forums/en/wow/topic/1021053914
1. "Hey, guys I made this cool Addon, you can download it over here for free! Please join my Patreon so I can eat and fix my teeth!" <- is OK
2. "Hey guys, here are cool screenshots of my cool Addon. If you pay $5 bucks, you can download it" <- is NOT OK
3. "Hey guys, sub to my channel. Subs get cool perks like PogChamp emotes and my cool WeakAuras" <- ¯\_(ツ)_/¯
(I think 2 and 3 are the same case, but I'm not Blizzard)