Whenever under any last will and testament or trust instrument of a decedent who is survived by a spouse, the executor, trustee, or other fiduciary is authorized to or required by the terms of such an instrument to satisfy a pecuniary bequest, including a pecuniary bequest in trust or transfer in trust of a pecuniary amount to or for the benefit of any beneficiary, by transferring or allocating assets in kind at their federal estate tax values or at any value other than the fair market value of the assets at the date of their distribution or allocation, then the fiduciary shall satisfy the pecuniary bequest or transfer in trust by the distribution or allocation of assets, including cash, having an aggregate fair market value on the date or dates of distribution or allocation equal to the amount of the pecuniary bequest or transfer in trust as finally determined for federal estate tax purposes, unless the will or governing instrument provides otherwise.