I can't give you a definitive answer, but apparently it doesn't work directly. I tried a Satechi multiport adapter with HDMI output and I can't get a signal on the TV. As a note, with the same adapter, I can watch Youtube and holiday pictures on a TV with a Galaxy S8+ as the output device, albeit with a loss of resolution.

I tried it with a USB-C docking station from Lenovo - it didn't work either. The only way to operate screen sharing is currently via chromecast or similar.

Addendum: I have just received the answer from Huawei support for Switzerland (within 60 minutes, well done).

In other words: The MediaPad M5 does not have the MHL/HDMI function, e.g. to mirror an image of the device on a screen via HDMI/USB connection. The Huawei MateDock would also only provide the USB ports at best.