MetaMask and Lido emphasized that their staking arrangement is non-custodial and that MetaMask does not manage or hold withdrawal keys for client stake.

From the articleMetaMask Security Incident Prompts Exit of Affected Ethereum ValidatorsAlso in MetaMask Exits Lido Validators Amid Infrastructure ‘Security Incident’ - Decrypt, MetaMask is exiting validators. Where does the staked ETH go next?