They don't care. It's not a big deal, they'll have them taken down and let the game continue as normal.
I'm sure half the playerbase is eagerly awaiting the big announcement of total lockdowns on mods, RP and addons and SE to file massive lawsuits left and right so they can dig into some juicy drama and type long self-righteous rants about how all those things are evil and WoW ruined the game ...but it's not happening.
They have better things to do with their time, they'll address any legal issues with those involved and they're well aware a tiny handful of idiots with a billboard don't represent the playerbase.
