I'm surprised you folks don't have that law yet !
Here the passport will be witheld owning the government any kinds of money (child support, taxes, outstanding fines/court fines).
To trinkle pinkle, yes, you do need to show a passport on all international flights, at check in !
Trust me, I flew from Florida, California, Mexico, Cuba, return a lot. Can't get pass the check-in point without a valid passport !
And passports these days all get scanned.
So, even if the validation date is still good in writing, does not mean it's good at the scanning point !