Some references to what could be the successor to the MediaPad M3 have surfaced online via an UAprof.xml file. The references point to a similar display resolution as the M3 and the OS version to be Android 8 Oreo.
https://www.notebookcheck.net/References-to-a-new-Huawei-tablet-surface-online-purportedly-the-MediaPad-M4.271460.0.html