Why did Amazon lay off most of their hardware engineering staff last month? There website for Amazon Fire TV says it is out of stock and no known date for restocking. That is not the indicator of a new product coming anytime soon. Perhaps you are right and they will go with something engineered by someone else. . . which may be why they let their own in-house engineers go.
Most? More FUD?
The news on new Fire TV devices has been available for over a month. Yet you claim it has been discontinued. Why?
They are sold out of the old ones. I suppose they could make more but then they would be selling outdated models when a new model is about to come out, sorta like some other gadget makers do.