No, not all 5,0L's came with AWD. All but one of mine where RWD and the one I bought that turned out to be AWD was advertised as RWD and I didn't notice that it was AWD until I got it home and removed the front hub caps while checking the brakes. Actually I was bummed when I discovered it was AWD as I didn't need/want it, living in the southern U.S.
For me the AWD adds unwanted weight and complexity, slightly poorer fuel economy, the need to buy tires 4 at a time and more stuff to break (front wheel hub assemblies, CV axles, front diff, driveshaft CV joint, t-case and oil leaks, added maintenance). If you live where it snows it's worth it. If you occasionally go off-road it's pretty good, but for serious off-roading a manual t-case is better.