They’re coated strings with the NYXL’s high carbon steel core, and, apparently, a new coating. My PS shipped with their coated 80/20s with the traditional cores, and sounded great. They recently changed the formula using the XL core, but perhaps not changing the coating (?), and while it’s good, it’s lost something.
I’m definitely going to try a couple sets of these and use them for a while, see how things go. If these don’t have it, I’ll switch back to an uncoated string; however, the extra life a coated string brings means I can use the acoustic on a last-minute project without having to do a string change, which I like.