Google only inspects the code when the app is submitted to Google Play. When you sideload an apk, all bets are off. A bad actor could push out an apk filled with malware.
By requiring sideloaded apps to be signed by a registered developer...
That is the current situation for the Go and Fly apps for Android, you sideload them after downloading them directly from a DJI site.
The issue being discussed is that Google will require sideloaded apps to be signed by a registered developer...
Unofficial word from someone at the FAA is:
It's illegal to fly a drone over 250g and over without registering and broadcasting but the FAA won't be chasing violators if they're over a few grams unless it contributes to an incident report.