I've been keeping an eye on the Honor 8 forums at XDA, hoping this info would become available eventually. According to a user post there, this is how you would flash an Honor 8 back to stock:
"If you want to restore to a completely stock phone, Huawei phones have a nice built in feature called e-Recovery. You can get into this mode through holding Volume Up when booting. (I believe the phone needs to be plugged into a computer at the time as well.) eRecovery will download the latest images direct from Huawei and flash the phone automatically. I've used it a few times to recover a device I've completely screwed up."
And here's the download link for the stock ROM from Honor's website:
detail - support
*NOTE: this is for the USA model, FRD-L04
Also note: I haven't done any of the above myself yet, so I can't speak to its veracity.
"If you want to restore to a completely stock phone, Huawei phones have a nice built in feature called e-Recovery. You can get into this mode through holding Volume Up when booting. (I believe the phone needs to be plugged into a computer at the time as well.) eRecovery will download the latest images direct from Huawei and flash the phone automatically. I've used it a few times to recover a device I've completely screwed up."
And here's the download link for the stock ROM from Honor's website:
detail - support
*NOTE: this is for the USA model, FRD-L04
Also note: I haven't done any of the above myself yet, so I can't speak to its veracity.