This makes absolutely no sense. The YPG's leadership, is committed, first & foremost, to protecting the Kurdish people from demographic re-engineering, not securing oil/ fighting ISIS. Unless the US protects the Kurds from the Turkish invasion, they'll just cut a deal w/ Damascus
This new insane plan Trump's people hatched appears to suggest that the Kurds will lose all their population centers in the north to the Turkish invasion, be displaced south to Arab-majority Raqqa & Deir Ezzor to live there, "secure" oil & fight ISIS. 
As far as the leadership of the YPG/SDF is concerned, it is better for the Kurds to live under an authoritarian Baath regime than endure demographic re-engineering - the openly stated goal of the Turkish invasion. This is why they cut the deals with Damascus & Russia.
This quote from a Kurdish official tells you all you need to know "if Turkey invades, he must flee the country with his entire extended family. If the regime returns...he can flee alone, and his family will be safe staying behind." bit.ly/2MulLYa From Jan 2019
