In 1995 Congress overwhelmingly passed a law requiring that the US Embassy in Israel be moved to Jerusalem. In announcing that he would finally put the law into effect, President Trump clearly stated that Jerusalem remains subject to negotiation between Israel and the Palestinians.
It seems to me that Trump hasn’t made any substantive change. But he has made it clear that the Palestinians will get nothing they want except through a peace agreement with Israel. This should not be an impediment to negotiations, as many are saying, but actually a strong encouragement to negotiate. If the Palestinians think it through and act rationally, that is what will happen.