Samsung Galaxy A8 (2016) may soon receive Android 8.0 Oreo
Galaxy A8 (2016) was recently spotted at Wi-Fi Alliance with Android 8.0 Oreo on board. The same thing happened with some of the smartphones Samsung updated to Oreo in the past, so there's a high chance that the Galaxy A8 (2016) will indeed receive the update.
Of course, Android 8.0 Oreo will be the last major update the Galaxy A8 (2016) will receive. In fact, next year will probably the last one that the smartphone will get security updates.
Samsung has been offering Android Oreo updates to a few mid-range Galaxy smartphones in the last couple of months, and it looks like the trend will continue throughout the year. If you own a Samsung smartphone no older than two years, there's a chance that you'll get an Android Oreo update at some point this year.