1995 Buick Park Avenue Need to Rebuild Engine at 150,000 mi

Engine Mechanical problem
1995 Buick Park Avenue Front Wheel Drive Automatic

I have a 1995 Park Avenue with about 140,000 miles. The car is in very good shape and I love it. My mechanic says that the engine on that car should have a "rebuild" at about 150,000 miles - if not, you run the risk of the engine blowing completely. Does this make sense? (My mechanical knowledge is minimal and the terminology of "engine rebuild" might not be accurate - bit it is some kind of engine overhaul costing in the neighborhood of $800 - NYC area prices)