The miraiam webster definition of ambiguity is using both hand equally. Taiwan and mainland China will never accept
this agreement. There are few threads that come on the EE board where I can give an expert opinion. This is one of them.
EDIT: Also, and I think this may be where the misunderstanding is, we're not referring to what China and Taiwan might respectively accept as an alternative to reunification but rather what U.S. policy currently is today. Apples and oranges.