Best answer by Max
Glad to hear that you are interested in improving your system software with a system update.
Regarding your question, I can inform you that the Mate 8 is not scheduled to receive the Android Oreo update. From the Mate series, only the Mate 9 can receive it at the moment. Since the Mate 8 is a pretty old device and no longer in production, at the best it only receives the Android 7/EMUI 5 update.
Hope this proves useful!