My bet is he goes independent and grabs some of the youtubers to start a channel. That or briebart hires him and starts a video news service.
I've heard this from several youtubers, but I'm having a hard time imagining it. I don't get the sense that O'Reilly had a passion for his message. I think he had a passion for the power it gave him to deliver that message.
It's hard to imagine youtubers going along with this kind of hostile behavior. Without the power of a network behind him, people are more likely to laugh at these kinds of antics on a youtube crew.
As other people have noted, O'Reilly's message is less attention-grabbing when the President of the US has already co-opted it.