I sure hope so. I'd consider that absolutely required, regardless of whether a multisig address is used, for security, to sign the contract and for tax purposes.
That would also allow to make sure the chosen treasurers are really different people and not related to each other, which worried QS.

Whatever security implemented at the moment can be kept and improved. Using a multisig address just adds even more security, nothing needs to be compromised as far as I know or has been exposed here.