Whether your phone is compatible or not that doesn't matter in case samsung, they have a update policy for every phone that means a phone has a fixed time of getting update, therefore it totally depneds on samsung whether they will give update or not. Remember you are not using Apple or Xiaomi, they give update to there old phone also iPhone 5 has launched year ago but it still has iOS 11 and redmi note 3, got marshmallow with miui 8 and now nougat with miui 9. #Update_on_samsung_sucks.
And if you so desperate for Oreo then simply root your phone and additionally you will also get many other features too. But it will void your warranty.
Thanks for reaching out to the Samsung support communities! Samsung constantly works towards bringing-out the best updates and incorporating the latest technology along with great features. However, updates are released through FOTA in waves only, so we’re unable to determine when your device will receive an update. We will notify you any update in this regard via FOTA. We appreciate your loyalty, thanks for sharing your concerns with the Community! Be sure to hit ♡ when you find an answer that works for you.
Further assistance, you can get in touch with us via Live Chat option by following- http://livechat.support.samsung.com/Customer_new/IN. You can also connect us via Samsung Members web community by following mentioned url-https://community.samsungmembers.com/en_IN#/
