Welll, your right, Paramount, or any other production company, doesn't care how it makes its money. They will essentially sell the rights to anyone that will pay them. But, a network which picks up a show would never allow a second simultaneous distribution. Unless I'm mistaken, the network has exclusive rights to a picked up show. They in fact pay for the creation(production) of said show. They basically own it. They'd never allow another avenue to watch it(first runs) unless they were taking a big cut themselves. Even then it would be doubtful. It would destroy their ad revenue.
Now after the show is cancelled its a different story. Apple, if it wanted to do old tv shows, could probably do it. I just think it would be a lot easier dealing with film, as there aren't things like syndication deals to deal with.
Of course, Apple could act like a network and compete directly and pick up shows itself. But thats a big cost and a big gamble.