I wouldn't pay to see anything on YouTube. Good luck to them getting people to pay for a brand name they associate with free (crap).
UFC is already in a category (fighting, or sports more generally) that people have shown some willingness to pay for, so there's some logic to that. But that doesn't mean anyone will pay for scripted drama or even reality-TV type shows on YouTube, not unless they are incredibly compelling.
A new Star Trek
series could whomp up that level of interest, but then the question is, why would CBS allow a premium brand (thanks to Paramount's efforts) to be associated with YouTube? Better to do nothing at all with a brand rather than devalue it like that. The brand names that are compelling enough to inspire paid viewing are too valuable to waste on the likes of YouTube.
Netflix has a better shot at that sort of thing. People already pay for subscriptions, so there's no barrier to sampling some original series they might develop. And they have more of a quality image compared with YouTube, so Arrested Development
doesn't have to be ashamed of the association. Whether those series can attract/hang onto subscribers well enough to make it worth Netflix's while is another thing entirely, but the only way to find out is to try.