I think this is more of an idea for a whole subclass of vaults, correct? Basically take the existing vaults and modify the strategy such that instead of swapping CRV or whatever for the underlying asset, it’s swapped for yUSD. This is effectively the inverse of the idea proposed here: Proposal: yCRV-ETH exposure vault, which is essentially a yCRV vault whose earnings are swapped into ETH instead of more yUSD.
I think this isn’t a bad idea, and would help eventually build out the ecosystem for a diverse variety of preferences. However, I would say these types of “alternative” vaults are probably a little lower priority right now.