Bitwarden requires that its contributors complete a contributor agreement which includes a fairly bulletproof Copyright Transfer Agreement. Assuming this has been applied across the board, it means that Bitkeeper is the sole rightsholder in its codebase. As we have noted here, the copyright holder is never beholden to the rules of the holder's own license grant, so although Bitwarden distributes this code under AGPL, they themselves are free to use it as they please, including in proprietary products, and in other uses that would not be permissible for a licensee bound by the AGPL.

As for your edit, removing Bitwarden's code and replacing it with your own (with a view to freeing the code from the AGPL) is fraught with difficulty, and is pretty much impossible to do single-handedly.

Bitwarden requires that its contributors complete a contributor agreement which includes a fairly bulletproof Copyright Transfer Agreement. Assuming this has been applied across the board, it means that Bitkeeper is the sole rightsholder in its codebase. As we have noted here, the copyright holder is never beholden to the rules of the holder's own license grant, so although Bitwarden distributes this code under AGPL, they themselves are free to use it as they please, including in proprietary products, and in other ways that would not be permissible for a licensee bound by the AGPL.

As for your edit, removing Bitwarden's code and replacing it with your own (with a view to freeing the code from the AGPL) is fraught with difficulty, and is pretty much impossible to do single-handedly.