There is a tweet from the official yearn account stating that historic CRV will be claimable, so not implementing that promise would be tantamount to fraud or in the very least highly misleading marketing.
It would be possible to compile a list of the rightful owners of the pre-launch CRV by building on top of the Python script that Michael used for the vesting calculation. Of course it might be that nobody wants to work on it, since at the moment, none of the three alternatives would make use of it anyway.
For the record, I was not a pre-launch investor in the vault so I have nothing to gain from this and in fact would lose from it. This is a matter of integrity over profits.