Other than sufficient length (preferably over 7400 yards), rough (4+ inches, please), and fast greens (13+) do you really need anything else to host a successful major?
If we have learned anything from majors at Torrey Pines or Hazeltine, it is that the course does not need to be GCA gems for it to host a successful major. Especially when the success is measured by the score relative to the par and who wins it.
Seriously, couldn't most muni's nearby could host a major if it was 7600 yards, can grow 5 inch thick bluegrass rough (with 25 yard wide fairways) and greens that can run 14 without killing it? Far as I can tell, bunkers are non-issues as it is more penal to land in the thick rough than the bunker.
Why do you really need great GCA to host a major?