Well, we heard Amazon was going to release an app a year or two ago too? Turned out to be fake news (just like this time, apparently). I mean why would Amazon give Apple a bone here? It has literally NOTHING to gain and everything to lose. Right now FireTV is leaps and bounds ahead of Apple TV sales (and rightly so, IMO with Apple's bonehead move to not include 4K). You can get Amazon Prime on a Sony PS4 even, but you cannot get Apple TV movie rentals on anything but iTunes and Apple TV. In other words, why should Amazon give Apple access to Amazon Prime when Apple would never dream of giving FireTV access to Apple TV/iTunes material??? Amazon gets nothing and Apple gets increased sales. Quid-Pro-Quo. IMO, Apple needs to give Amazon something of value in return (i.e. maybe Airplay compatibility in return for a Prime App viewer?)
Of course, Amazon does similar when it comes to something like Vudu. Fortunately, unlike Apple TV, Amazon FireTV is a largely open system (i.e. you don't need paid developer status to side-load 3rd party software). So where I can only get MrMC on AppleTV at best, I can get full Kodi on FireTV with a free side-load. I just recently installed a 3rd party Vudu App for FireTV that now gives me access to my Ultraviolet HDX digital copies on my two FireTV 4K units and SDX on my FireTV stick (Amazon wouldn't approve an official one, but as long as the platform is open to side-loads, someone can always fill the gaps with modified Android Apps that support Amazon specs and remote control). There's a certain irony that my PS4 has a better selection of usable video streaming Apps than Apple TV or even FireTV without side-loading (Vudu video quality streaming blows away iTunes IMO; I had a hard time telling the stream from the BD where you can usually spot at least some dark lighting banding issues on iTunes encodes sooner or later). I can even remotely control and play games on my Mac from the PS4 with the Sony Playstation App and one of my dual shock controllers. It'd be nice if I could play Mac games on the PS4 as well in return, but Apple doesn't care about games while if I had Windows 10 and XBox, I think you can play both directions?)