For a company the size of Apple (with their exhaustive resources and long history), a comprehensive preproduction test that tests the action of upgrading a lot

For a company the size of Apple (with their exhaustive resources and long history), a comprehensive preproduction test that tests the action of upgrading a lot of the software... that should be within their capabilities. As in "don't just approximate what the users will be doing, actually do what the users will be doing".