I notice you're asking about a "helpful paper" regarding updating the to Android 10 .
Its last major official update was to Android 7.0 (Nougat) with EMUI 5.0. Huawei never released an official Android 8, 9, or 10 update for the P9. huawei p9 update android 10
I want to provide some important clarification: I notice you're asking about a "helpful paper"