Who will be allowed to make Ubuntu Mobile OS phone hardware?

I'm a little puzzled by the Ubuntu mobile OS news. I think the OS looks promising but my main question regards building the hardware. Who will be allowed to build it? Last year Acer was set to make a phone for the Aliyun OS but Google put a stop to that. My understanding is that Google would withhold support because membership in the Android alliance forbids working with Android forks (or something like that, please don't hold this against me).

Now I know that the Aliyun OS was more of a blatant ripoff of Android including pirated apps in their app store but aside from using less of Android than Aliyun is how is the Ubuntu mobile OS different from that situation? They're not using the Java VM layer but are using the core but since this has Android origins I'm curious if anyone knows how this will be different or if it is at all.