They were not mentioned on Hoover’s site, but the photo at Tractor Supply showed a barred hen. I know a solid rooster over a barred hen produces a sex link, so you could be right about the cross.
I’m not familiar with them either, but I just bought six at tractor supply this morning. They get their chicks from Hoover’s Hatchery, and I assume it’s a cross they have developed. I’m going to check Hoover’s website first chance I get.