The ban actually is from US side, Google is just abiding the guidelines.
You can easily deploy your application in AppGallery using Huawei Mobile Services.
Almost all mandatory services are covered as of today, rich community and developer forum support is also available if you stuck up in development or deployment.
In order to deploy your app you can follow up below steps.
Use HMS Toolkit to identify the dependencies.
Once services are identified you can add them in your application.
Codelabs are available to practice as well.
I would recommend to have a single codebase and just switch to GMS or HMS depending on device where your app is downloaded.
Most of the major apps are using same functionality now a days.
Codelab
Developer Forum
Official Documentation of services
I hope this helps you.