technically 3rd party addons has always been against the ToS and every time it comes up yoshi says "don't do it" just because he also says if your not doing anything to hurt anyone your likely safe is by no means a guarantee.
If they're getting waves of complaints from people angry about streamers using addons, acting on it is probably what they'll do since in my opinion getting a ton of complaints is the very thing they're trying to avoid the most
Their plan is to add in the functionality of every addon they find unoffensive. They're giving the people that want the addons what they want, while disarming the complainers forcing them to enforce the ToS, and keeping the ToS intact which is important for their game.
Kind of addressing everyone's needs in the best way possible but it will take a little time.
Allowing addons in ToS is basically insanity, look at WoW... the raids there are designed around addons being used. It's a ridiculous model