They need to do a reality check before going with another arm64 alternate OS.
Like, why would anyone would change their OS, if the one they use is already stable? Are there everyday apps that they need in that OS? What are its compatibility level with Google apps, like if I have Google drive, is there any apps that can access it from there too? Most people doesn't run 2 apps for similar usage. If I use Google maps, I certainly hope all my data like home, pinpoints and everything doesn't need to be manually imported/sync with another app. And if I encounter some problems with the devices, would I easily get some help? Because at this time people would only knows just 2 mobile devices OS, Android or iPhone. Why would other manufacturers use this instead of Android? Why would developers would create app in there? Because they will have another burden: support app in another platform. Remember, many iOS app developers drop support of their Android app because they barely able to maintain 2 different ecosystem. Unless they use a framework like Flutter, wait, oh even Flutter is from Google. Cupertino doesn't bother to do the same, they just like app developers to create apps only for iOS. And Framework mostly cripples user experiences. And many more of these problems.
If they don't come out with best answers for those questions and tackle those problems, it's just another dead on arrival OS. They way I see it from a honest review of GSMArena, which they try to live a week with Huawei without Google: it's no go for most people. That's still an Android, without Google apps. Let alone an entire OS with totally different ecosystem.