I don't think they can. They will always need a fall back but more importantly, to retain a strong negotiation position of strength, they can't leave themselves at the mercy of the TV makers for getting Apple content on screen. Samsung and others can now sell their TV's with the incentive of "save money on an Apple TV by getting it built in". No ATV and there's no sweetener in the sale anymore.
Apple did well to persuade so many to include it in their TVs.
Remember that an ATV box only needs to be sold at cost price by Apple. The money is made in services and consumables. It's like the ink jet printers which were sold dirt cheap only for us to be price gouged for the ink refills. So it doesn't matter if they don't make a profit on ATV, we know they do from their services business.