Yes. ERC-4337 wallets could greatly benefit from using DiamodStorage and I hope to see wallet developers use it.
The benefit goes beyond just adding functionality via new facets. It also keeps accounts safe when switching them to a new implementation. Wallets are likely to use proxies, and the users may want to switch implementations. For example, a user might start with a simple wallet, and later decide to switch it to a multisig or a wallet with social recovery. There’s a risk that the previous implementation’s storage will break the security of the new implementation by leaving unexpected storage behind. I demonstrated it by leaving shadow signers in Gnosis Safe.
If both implementations were EIP-2535 facets that use DiamondStorage with different base positions, switching between implementations becomes safe.