Yes, it works, but select accounts only (YMMV)...
Amazon has the Amazon Fire TV Stick 4K Streaming Media Player with Alexa Voice Remote (3rd Generation 2018 model) for $49.99 - $25 off with code 4KFIRETV
at checkout [Exp 12/31] = $24.99
with free shipping on $25+ or with Prime.
Update [7/18]: Now available to all customers for $35 with free shipping. Select accounts can still purchase it for $25 with code 4KFIRETV at checkout.
The latest Fire TV Stick has 4K, Dolby Atmos, Dolby Vision and HDR 10+ support plus a remote with programmable buttons for TV, sound bar and receiver.Amazon Fire TV Stick w/ Updated Alexa Voice Remote (2019) for $20 w/ code FIRETVSTICK at checkout (select accounts, YMMV)