Some Huawei mobile devices don't have the Google Play Store and have the Huawei AppGallery instead. Since Flutter is for cross-platform development (iOS and Android), it may be desirable to propose Flutter developed apps through the Huawei AppGallery.
The Huawei devices without the Google Play Store are still using Android and the applications to upload to the Huawei AppGallery must have the apk extension (just like in the Google Play Store). These are hunches that at least some Google Play Store applications can be proposed on the Huawei AppGallery. However, I did not find any proof or confirmation of this. Nor any clear perimeter for this compatibility. For example, some services may not work or may not be accepted on the Huawei AppGallery for technical or legal reasons. One part of this perimeter is the use of Flutter to develop the application.
So, my question is, can a Flutter developed application be compatible with the Huawei AppGallery and if so, under which conditions?
Edit after first app publication 2020 04 13
My first Flutter app has just been published on the Huawei AppGallery. This answers the first part of the question. Still, as this app is quite minimalist, this doesn't answer the most important part which is: under which conditions can a Flutter app be published on the Huawei AppGallery?
As long as your application complies with the regulations of AppGallery, there should not be any problem it. https://developer.huawei.com/consumer/en/doc/30202
AppGallery does not have any restriction on the language application developed with, no need to worry about it; flutter, cordova, react.native, xamarin they are fine.
Just a point to take care. If you are using SDKs or services those depend on Google Play services, when you have published your application on AppGallery, it will be visible only for Huawei devices supports Google Play Services.