If somebody say that Oreo is coming to our device, belive me, it's a lie.
I asked some of the Huawei staff and they said that no Huawei p9 lite 2016 will receive oreo.
If you are dying for android 8.0, Meticulus has developed it. It is still in beta.
Or you can wait until somebody ports oreo from s different device (if possible)