It is better to get it directly from the source as @Annoyed pointed out. If you read it the policy is:
Weight system – for all locations EXCEPT the Americas, point-to-point flights between Hong Kong and New Zealand* and point to point flights between Hong Kong and Qatar.
Piece System – for Central, North and South Americas (See Note 3)
- Economy: 23kg (50lbs)
- Total dimensions of each piece must not exceed 158cm (62in)
Applicable if you are travelling to, from or via the USA, Canada, select Central and South American countries.
The weight of any single piece of checked baggage should not be over 32kg (70lb). Acceptance of any bag weighing more than 32kg (70lb) is subject to prior approval and notification upon booking/ reservation. Overweight items (Exception: mobility aids, medical equipment, sporting equipment, musical instruments, camera equipment, household effects, pets as baggage and diplomatic baggage) will be repacked or split into lighter units during check-in otherwise will not be accepted for carriage.
Any bag exceeding the total dimensions of 203cm (80in) (width + height + length) will not be carried as accompanied baggage unless prior notification is made with us upon booking/ reservation and approval is granted by us.
At issue is applicability of luggage weight for your flight from Hong Kong to Malaysia, which if part of the single itinerary is basically the same trip from US via Hong Kong to Malaysia.
If you purchased 2 tickets separately the story will be different.