Only change I can spot is a minor one to Rule 5 (Reservations and Ticketing)
Old wording:
…
Where the applicable booking class for the lower class is not available,
Passengers travelling on First Class Fares may book Y class
Passengers travelling on DONE* Business Class Fares may book B class
…
New wording:
…
Passengers travelling on First Class Fares may book Y class
Passengers travelling on DONE* Business Class Fares may book B class (except AA) or H class on AA
...