Palestine is the name of an area of land. Not a jurisdiction. Not a nation state. Not a legal authority.
Talking about Palestine is no different than talking about Appalachia. In the sense they both have specific cultures, etc. They are part of various states and/or countries with different legal jurisdictions.
I'm not seeing the major screw-up by Trump since the region has been called Palestine my whole life and the State is something new. Definitions change but the reality is that both the Israelis and the Arabs in that region are all residents of Palestine based on what was taught in schools up until the late seventies or probably the mid-eighties.