While still not officially confirmed, there is growing evidence that the Galaxy S8, S8+ and the Galaxy Note8 will be getting Samsung's Android Pie-based One UI soon. Especially after the three handsets just passed the WiFi Alliance's certification process. Galaxy S8, S8+ and Note8 The screenshots above are taken straight from the WiFi Alliance website and list handsets with model numbers SM-G9500, SM-G9550 and SM-N9500 which are all Chinese variants of the Galaxy S8, S8+ and the Galaxy Note8, respectively. Unfortunately, the listings don't reveal anything out of the ordinary...
Source: https://www.gsmarena.com/android_pie_for_the_samsung_galaxy_s8series_and_note8_is_on_its_way-news-34199.php