The anti-freeze in my Carrera has never been changed!
If it ever gets so cold the my coolant freezes I will have bigger problems to worry about.
On my El Camino I change the anti-freeze every other year.
I suspect lifetime coolant is just like lifetime transmission oil. Just a sales gimmick to make the maintenance cost look good to the first time buyer.
A friend of mine had a Ford that had over 100.000 miles on it when he decided maybe it was time for new spark plugs. They were pretty much welded into place.