Yeah I don’t think many round here in Califrornia would be particularly offended if I used it, more confused really!We definitely don't refer to ourselves as "yanks"
That said, if someone called me that, even in a somewhat derogatory fashion, it'd never cross my mind that it might be "xenophobic."
Might be different in some of the Southern states though.
Anyhow Friedkin - they sound like a tasty Southern dish tbh.