During the period when Huawei introduced the HarmonyOS operating system, there were speculations that their future phones will make use of that over Android. Since then, we have since the announcement of the Mate 30 series which still ships with an AOSP build of Android and it is notably lacking Google Mobile Services (GMS).
Huawei’s President of Global Media and Communications, Joy Tan confirmed that the company will continue to use on Android for its phones in the near future as switching to a different OS would not only require several years of work but would also be detrimental for consumer confidence. With so many Huawei users dependent on GMS, the company would rather focus its resources on further expanding its own Huawei Mobile Services to serve as a replacement.
Without a strong app ecosystem, Huawei will not be able to offer its international users a viable choice. On the other hand, enticing a large enough developer community is no easy feat but it would still be the logical move for Huawei at this point.