No, it's contractual. Netflix cannot act as a "broadcast" service due to the way they license content. It means that there is a limit to how many pieces of content they can play without any user interaction (a user-interaction will classify the play as "on-demand" as opposed to "broadcast").
(Yes, I'm a former employee who worked on the auto-play feature).
(Yes, I'm a former employee who worked on the auto-play feature).