It means that after version 1.33, Amazon devices will no longer receive new updates, the game will be taken off the store and at a later date, version 1.33 won't be supported anymore. 

You can continue to play on your Amazon device for a time, but we strongly suggest that you continue playing on a non-Amazon device. You can do that (and keep your progression) by signing into Facebook on your Amazon device, and then, launch the game on your new device of choice where you will be offered to sign into Facebook as well. At that point, your progression should appear on your new device.