Not that you were planning on buying twice.
Fallout 76 is coming to Steam with the Wastelanders update, and no doubt many of you are wondering what this means for those who already bought the game on Bethesda.net. The good news is that Bethesda for once won’t be expecting you to buy the game twice.
Up through April 12, anyone who owns Fallout 76 on Beth.net can link their Steam account and receive Fallout 76 on Steam for free.
Of course, many of our PC fans who have played the game through the Bethesda.net Launcher would also like to have the option to play on Steam, so we have a special offer just for you. From now through 11:59pm ET, April 12, if you have already purchased Fallout 76 on Bethesda.net, you have the opportunity to get the game on Steam, including Wastelanders.
The news post does note that your atoms and Fallout 1st membership will not transfer and atoms earned are specific to their platform, however your purchases will cross over. Game progress does carry over. Players with a Fallout 1st membership are encouraged to contact customer support to see what options are available.
Source: Bethesda