We all know that we abandoned the Kurds and pulled out of Northern Syria, but if you read the 2019 article you will see that we did not abandon Al-Tanf base.
From the NYTs article in your post.
“”The United States also maintains a small contingent of troops at the Al-Tanf base in south-central Syria, as a deterrent to Iranian movements in that region. The withdrawal order will not affect that post, an American official said.
The garrison at Al-Tanf, for now, is viewed as critical to protect Jordan and to counter Iranian influence, and Mr. Trump has not pushed for any withdrawal from there.””