https://www.reddit.com/r/Huawei/comments/1bwwt9n/google_play_store_with_microg/

If you install the latest microG posted on GitHub and use Gbox Google play store you will discover the amazing thing that anything installed is outside gbox running without virtualization and does not depend on gbox at all. Phone tested: P60 pro.

So while your Google play store app is virtualized inside gbox, anything else is not, and somehow play store has access outside gbox and you can also update any app installed through play store or outside it. Literally like you use aurora store.