If 3rd party content providers like magazine/ezines are allowed, it is all how you allow them and how they are in the user interface and what type of control you give to the user to either see there posts, or not. Facebook is sh*t, hardly any control. What about giving those content providers and Steemers 1) each content provider there own channel, 2) optin to the user for channel 3) maybe a general post channel, but again channel, like promoted a channel is in Steemit, you don't have to look at it. In this way, post will not be part of New channel, unless you as a user optin for the content channel.