As announced weeks ago, Bethesda is stamping out its own Bethesda.Net launcher and pushing the community to Steam. Now there are specific dates for this.
Bethesda is retiring the launcher that you used to use to run your accounts and download games, and it’ll be doing so very soon. As of May 11th, it will no longer be possible to log in via the launcher.
But don’t worry, your accounts will not be lost, because everything you own there will be transferred to Steam. On April 27th, a tool will guide you through the migration process to transfer your Bethesda.Net account to Steam, or at least the contents of it. The link to the tool should be made available to the account holders in a timely manner.
However, you must be prepared to have to completely re-download any games that you previously operated via the launcher. Existing subscriptions will remain in place, but will not be automatically renewed. Otherwise, access to acquired in-game objects, currencies and the like should remain completely intact. Only with trophies that are based on game progress, you might notice some losses.
At the same time, the sale of gaming products via the Bethesda website will be completely discontinued. You can find more information about migration in a FAQ created for Fallout 76 players.