Samsung sells. If the A5 for 2017 winds up with a curved screen, it's a good bet that the upcoming Galaxy S8 will have it, too.
The next update to this year's Galaxy A5 is also rumored to have:
5.2-inch 1080p screen with Gorilla Glass 4
16-megapixel front and rear cameras
32GB of storage
3GB of RAM
Aluminum frame, with glass back cover
USB Type-C port
Samsung declined to comment on the Galaxy A5 specs for 2017.