Android 9 Pie has now been released, and manufacturers are already planning future updates to their current devices (though Essential beat the competition and released their update the same day). Huawei is the latest to talk about its update plans.
EMUI 9.0 based on Android Pie will be unveiled at IFA 2018 in September. From there, the P20 series will receive the update to Android Pie first. This is scheduled to happen in September, which is surprisingly fast. This might be due to Project Treble, though we don’t know this for sure.
The next device to get the update is the Mate series, though no time table was given. Past that is unknown as Huawei hasn’t shared which devices will and won’t get the update.
We’ll have to wait and see if Huawei can make the September deadline. The company has been pretty decent about supporting its flagships, but updates have often been slow and older devices have been forgotten about.