Yes, YA Historicals are being published. BUT, the marketing to teens usually downplays the historical aspect. Most librarians, both school and public, noted that when they mentioned "historical novel" to a teen, they usually equated that with history class and immediately lost interest. While adult readers may hear Historical romance and envision the wide expanse of love and romance set against the pageant that is history (or something like that), the teen stops listening after the "h-word". So they need to be marketed as something else.
The back cover begins with three heavily emphasized words: Passion. Lies. Betrayal. The information that the novel is set in the court of King Henry VIII, is done briefly and in a much smaller font.
The inside copy also emphasizes the "glittering new life of fabulous gowns, opulent parties, and dashing men..." as well as the "secrets and lies, trysts, and back-door deals." The marketing relates to the themes, not the backdrop.
The long and short of it was that YA historical novels are still viable, and librarians will recommend them to teens, but the way they are promoted to teens matters. It has to take into account the possible reaction that the teens may experience with something that may at first appear school-related when they want something to read for fun.