The original Samsung Galaxy J7 could receive Android 7.0 Nougat update soon
Otherwise, we can't explain why the Samsung Galaxy J7 (2015) with Android 7.0 Nougat on board recently received its Wi-Fi certification. The device is listed with model number SM-J701M, one of the many model numbers that the original Galaxy J7 was tagged with since its release.
If Samsung will indeed push Android 7.0 Nougat to the Galaxy J7, it would be the second major OS update the smartphone received in one year. Samsung's mid-range handset was launched with Android 5.1 Lollipop right out of the box, but an Android 6.0.1 Marshmallow was released last year.
In any case, Android 7.0 Nougat will be the last major OS update the Galaxy J7 (2015) will receive, so it would probably be best to switch to a newer device if you want to benefit from all the new features and improvements included in Android O.