There's absolutely nothing stopping the author from distributing his app in following ways:

- on F-Droid, an app store dedicated for OSS software

- on Samsung Store, an app store preinstalled on most Android phones sold in US and other western world

- on Amazon store

- on Huawei app store

- on their own webpage as a downloadable APK

But what they really want is to use Googles distribution system while not paying the margin.