I was not aware that we could not load planned gifts from the deceased donor to link realized revenue received from a Foundation established as a result of the estate plans.  What do other organizations use as a work around for this?

We 'realize' the revenue when we book the present value planned gift - that's part of standard accrual accounting. Without knowing what type of planned gift you are talking about (build up annuity, CRT, Life Insurance, etc.) I can't really speak to a specific situation. If we receive an overage on what the present value of a planned gift was - we treat that as a new cash gift. If we receive less than anticipated when the gift was booked, we manually submit a note to accounting to indicate the loss - as part of cash flow not revenue.