The Kurds have been betrayed numerous times. America betrayed them at least twice in my memory. So they are likely to be very careful about any assurances we give them, especially since they are well aware that there are forces in America that would love to leave them dangling once again.
Also, Turkey would be strongly resistant to an independent Kurdistan, even if it did not include their own Kurds. An independent Kurdistan would be a magnet for Turkish Kurds in the future, regardless of any promises made now.
Still, it may be a possibility. I'm sure everyone in the region is considering it.
The best assurance we can give them is not good enough, but any is better than none.