Not really sure on total lifespan but I know that they are considered short lived. They are grouped in the fast growing, fast dying, and invasive catagory. They are good if you have the room, water, saw, and time. They require pruning 2-3 times a year with hand shears to lift branching from touching the ground. They require to be cleaned up in the canopy due to the branching growing into each other if you want a cleaner look. They have a shallow root system if they are not located near open water or flood irrigation.
I have 4 in my yard. One that I keep at 10 feet and three by a pond. They are young but I am guessing that they live around 60-80 yrs.
Maybe? Maybe not?