Now it seems that was just the preliminary list, since the company is already working on bringing the new software version to the even older P9 and P9 Plus. The news comes straight from a Huawei product manager, posting on its forums in China.
Huawei P9 Plus
There’s no release timeline mentioned, only that the update will be made available at some point. Currently the team is busy adapting the software to the P9 and P9 Plus. Note that since this hasn’t been announced on an international forum, there’s a slight chance that Huawei will only grace these phones with Oreo in China. We’re hoping it doesn’t forget about its sizable customer base in other countries, though.