Every week, Bethesda posts an update about the game in a blog they call Inside the Vault. The most recent post, published on January 1, muses on their ambitions for 2019. This includes both bug fixes and what will be the first content update.
"Later this month, we are providing resolutions by way of new patches for Fallout 76. Like our December 11 update, we will have a big update that will address many of the issues you've been providing feedback on. Full patch notes will follow soon.
We're also building an incredible list of future updates that we can't wait to share, including new quests, weekly in-game events, new Vaults opening, a new PvP mode, Player Vending and much more."
Since the game's release last November, most of the development team's focus has been on bug fixes and quality of life improvements. Considering the game's buggy state, this was probably the best choice. It's good to hear that they're not stopping there, though. Content updates will keep the game fresh for their most loyal players, while also incentivizing old players to come back to the game.
I'm just happy that we'll get to know what's been hiding in those dang vaults.