https://www.gamespot.com/articles/fallout-76-how-mods-and-private-servers-work-and-w/1100-6462371/

Fallout 76, like previous games in Bethesda's franchise, will feature mods, but how will they work with the game's new always-online, multiplayer focus? We chatted with Bethesda marketing boss Pete Hines recently, and he told us that mods in Fallout 76 will only run on private servers.

"Mod support is going to be tied to work that we're also doing on private servers, and letting people do private servers. Mods will be a thing that run on private servers," he said.