Pinal Air Park is used by some airlines, not all. United uses Goodyear Airpark just west of Phoenix. American uses Roswell, NM Airport (old USAF base).
747's usually go to Mojave Air Base/Victorville in CA, because that's where they specialize in either freight conversions or parts breakdown.
Lots of them, regardless of destination, end up in San Bernadino Airport in CA because that is where the best "reverse build" demo site it. They literally take apart aircraft down to the skin and recycle/resell the parts back into circulation.
I've been to all of them. Pretty cool to see aircraft sitting in a boneyard.