Pretty sure Bethesda said that the only mods that they are going to allow are decently sized ones that could be classed as DLC, they also said that they will quality check the mods coming through.
Might be wrong though.
Also, I'm not entirely sure why everyone's over-reacting, they couldn't give a shit if you pirate their stuff, they make more than enough money from everyone else anyway, they won't be like "Oh shit boys, Bob says he's gonna boycott us and pirate our shit, we need to cease this immediately so we can keep getting his money from our games"
At least Bethesda actually appreciates modding, compared to the guys in suits over at Take-Two who have no idea what modding actually entails and just want the money from GTA Online.