Huawei works on their own OS
Although USA has recently banned the sales of Huawei devices and technology to Americal companies, Huawei's plans to take over the primary spot in tech industry go on. Because Google is an American company, the govermnent may ask them to cancel all contact with the Chinese company which is exactly why Huwaei believes it's best to develop their own OS in order to replace Android.
We know that Huawei uses EMUI on their devices, which is based on Android, and introducing their own OS Huawei considers to be a strategic decision because they want to be ready for the possibility that they would be denied the option to use Android. That's why the company started developing their own software 6 years ago.
Huawei and Google have a long lasting collaboration, and nothing should stand between these two companies, but as we can see, Hauwei leaves nothing to the case and wants to have an alternative if push comes to shove. There's no doubt that Hauawei is better, more accepted and more recognizable together with Android, but there's no doubt that Huawei's OS will be a very stable software.