Bethesda have confirmed that Fallout 76 will not launch on Steam and will remain exclusive to bethesda.net in November, according to the official Fallout 76 site. This is also means the pre-order beta can only be accessed through bethesda.net. It's quite a change from Bethesda, as their entire catalogue of games can be brought on Steam. Presumably this move away from Steam is to avoid Steam taking a cut of the sales (30%) however, it could be argued that Fallout 76 will reach a smaller audience due to many PC gamers preferring to use Steam.
The impact this move may have on customers could be larger than is realised. Whilst many may cite that Steam is not perfect, it does however, provide a refund service and a customer-based review system - something that is lacking on bethesda.net. Over the last few years, there have been many complaints from customers and developers regarding the Steam review system, maybe Bethesda feel that the review system could hurt Fallout 76 sales. Despite Steam's efforts, the review system is not perfect, but it has undergone surgery multiple times to make it better for both parties.
Drifting away from conspiracy territory, there is some good news. When the beta for Fallout 76 drops, it will 'hopefully' be the full game, with any progress made within it transferring to the full game. Not everyone will like the sound of that, but it may provide some relief to those that do. Either way, it looks like the beta will be more of a network test to identify the resiliency of the multi-player aspect of the game.
Post below! - Adam Beddall