Didn't Nitro used to run for three hours?
During it's bad years, yes.
I worry we'll just get MORE Cena and main eventers with them having more segments, you know like on the current 3 hour RAWs that don't benefit new talent and tend to be worse than the 2 hour ones.
Other rumours are the 3rd hour is just temporary, it'll turn into a "Preview Hour/Show" and be switched to the WWE Network as a lead in and this is just to bridge the gap.