This was discussed when the new award scheme was announced, and the answer is that you can be allowed to go to Asia1 (PEK) via Asia2 (HKG), but must pay for the higher mileage value of the 2.

That means instead of an US-Asia1 award, you need to claim US-Asia2.

I assume you claimed US-Asia1? Ask if you can keep your existing itinierary if you redeemed miles for US-Asia2.