We had a PR to add Huawei support to Android, but never added the notification server support for it and eventually closed it: implement Huawei push notifications by adbenitez · Pull Request #3646 · deltachat/deltachat-android · GitHub
The problem with it is that it requires adding proprietary dependency from Huawei Maven repository, so we cannot do it in our applications released to F-Droid and Google Play, and will need to maintain yet another “flavour” (variant) of the app for this.
More realistic path forward is adding UnifiedPush support to Delta Chat (Implement push notifications through unifiedpush) and then someone releasing an UnifiedPush distributor that uses AppGallery Connect, similar to how gCompat-UP distributor uses Google FCM: gCompat-UP (Google) - Android | UnifiedPush
This way Delta Chat will not have to maintain yet another push notification service connection and Huawei dependency will be contained in a separate “distributor” application.