Non-public streams wouldn’t be published without DRM, or at least not as publicly retrievable (i.e. without any authentication) M3U playlists, would they?
Definitely a lot of these are also [re]broadcasts from vendors, probably for a specific platform or distribution target, that people found the URLs for and that the original source isn't super aware of the details of
https://iptv.example.com/720p.m3u8? I doubt you'll convince many courts of that being nonpublic.