I’d argue that WoWhead is 1.5th party website. Considering even Blizzards FAQ’s and Support Menus advise you to checking WoWhead before asking questions through the Official channels.
Not official, no. But Blizzards Official Websites, Officially advise you to check it first!
And lets face it, the amount they’re pushing Diablo Immortal at the moment, they’re pretty much on Blizzes payroll anyway.