We of course don't know it, but if the US is really saying it is adhering to the one china policy in bilateral meetings then proceeds to doing this, we will have a rough ride as the entire world. If that's the case China will not trust anything America pledges going forward. Two of the world's most powerful countries not trusting each other is horrible for the world. In previous cold war humankind avoided nuclear armageddon multiple times thanks to diplomacy. Lack of trust will make diplomacy mostly impossible.
Also, China is not going to allow the US to change the definition of one china policy. One China policy is a political compromise by China. It is frankly an absurd one with no precedents in history. China is not going to allow it to become even more absurd, especially not while it is much stronger than it was during the times original policy was being negotiated.