The current comment indicates that the function is adding a contract authorized to put messages into the rollups inbox, but the function itself is setting an outbox contract and registering it with the bridge, rather than directly dealing with the inbox.
https://github.com/code-423n4/2024-05-arbitrum-foundation/blob/6f861c85b281a29f04daacfe17a2099d7dad5f8f/src/rollup/RollupAdminLogic.sol#L113-L121
Heres a revised version of the comment to more accurately reflect the functions purpose.
