Spousal support orders end on the death of the payor, unless they specifically state that the support is binding on the debtor's estate. Lippolt v Lippolt Estate, 2015 ABQB 118 at para 92 held that a separation agreement setting out spousal support can bind the estate as long as there's an enurement clause though. Support might even still be payable if the recipient dies, which is absurd.

The issue is that if for example an agreement provides for spousal support of $3000 per month for 10 years, that's $360,000, which could be the entire estate, meaning that the former spouse could receive everything, even if there are dependent children from a new relationship.

Instead, they should be making a claim for Family Maintenance & Support against the estate. FMS claims look at the remaining property and try to find a way to fairly allocate it between all of the dependents. That way one dependent doesn't automatically get a leg up over the other dependents.