Most of what Donald Trump says and tweets can be ignored. His advisers and cabinet will make all final decisions regardless of what the stable genius says he will do—for instance, leaving Syria.
The US military isn’t going anywhere despite Trump declaring he will bring the troops home. The troops aren’t going anywhere so long as Bashar al-Assad remains in power.
Tump now says he wants to steal Syria’s minuscule reservoir of oil and give it to the Kurds, possibly as a consolation prize for abandoning them to Erdogan and Turkey.