The same thing has been told referring to the Windows Phone 7 Marketplace though
If it’s good, and Huawei follows up on making it truly open source, I suspect every Chinese manufacturer would at least have a line of Harmony OS phones, because they could always be the next trade war target.
And once the Chinese manufacturers are supporting it, you can also add a huge chunk of the South and South East Asian markets as your customer base as well, since a lot of users in those areas basically just buy the latest Xiaomi or Huawei phones.