E.K. Johnston’s novel Ahsoka has made it to #1 on the New York Times’ Bestsellers list for Young Adult hardcovers, per Lucasfilm’s Jennifer Heddle. The October 30th list isn’t online yet, but Ashley Eckstein has a shot of the print version.
This is far from the first Star Wars novel to make it to #1 on an NYT list (several novelizations and Heir to the Empire) but I believe it is the first YA to make the list at all. (Of course, keep in mind that the Star Wars YA novel is a very recent phenomenon, unlike the adult and middle-grade lines.)
I’m not exactly sure why they called this a YA novel (other than maybe for marketing purposes.) I’m halfway through it and it doesn’t seem any different from “A New Dawn” or “Tarkin,”
Because it’s published by Disney-LFL Press, mainly. Formally, the franchise hasn’t really done much YA, ever, but with the genre getting so hot in the last few years, it makes sense to aim some things there specifically. There’s a big audience that’s worth cultivating.
But truth be told, the recent Del Rey stuff does veer closer to YA territory than some other SF/F books, mainly because that’s how the franchise works, really. (Or is supposed to, anyway. They did try to up that in mid/late Legends, with mixed results, but that was a different era for books in general.)