YOUTUBE Kilar also talked about an advertising-supported HBO Max and agreeing with Disney boss Bob Chapek on theatrical windowing post-pandemic during an appearance at an investors conference. WarnerMedia CEO Jason Kilar talked about expanding the world of Harry Potter for HBO Max and Warner Bros. during an appearance at an investors conference Thursday. "There's this little thing called Harry Potter, which is one of the most beloved franchises. And we're incredibly thankful to be able to partner with J.K. Rowling and so I would argue there's a lot of fun and potential there as well," Kilar told the Morgan Stanley Technology, Media & Telecommunications Conference during a session that was webcast.