More than a week ago, I discovered that Huawei started sending EMUI 9.1 as a beta version of Chinese samples from Mate 20 and Mate 20 Pro. Now came new information!
It appears that EMUI 9.1 includes, among other things, GPU Turbo 3.1. This feature means that the phone optimizes performance so that the device does not attract as much energy as it was otherwise done. In addition, Huawei added a new "filter" that will make the interface more modern.
You can read all the new features and functions here.