The broker told the executrix, if the IRA proceeds from the estate IRA are directly transferred to inherited IRAs in the names of the estate beneficiaries, the proceeds would not be taxable to the estate.  The beneficiaries would have to withdraw the proceeds within 10 years.  The transfer into the beneficiary IRAs was done before 12/31.  As far as I know the beneficiaries have not withdrawn anything from those IRAs.  However, I'm not their accountant.

So, the executrix provided the brokerage firm with all of the beneficiary info.