If you are running an Android version that legitimately bundles Google Play, the Android release itself was either directly shipped by, or shipped by someone controlled by Google.

I am not saying we shouldn't care about problems because there are bigger ones. However, if the problem you are trying to fix is "Google is capable of poking around in your running instance of Signal" (That is, what the map trick is potentially capable of), then removing any Google integration from the Signal app will not help as long as you still run on a Google-controlled Android release.

The only unique thing about this specific Google dependency is that it is more dynamic than the OS, but as long as Google owns your OS, they have every possibility of monitoring your process memory. That's before you start worrying about the black box proprietary drivers most ARM devices use and all that jazz.

My complaint lies in that fixing this will not improve the security by any noticable measure (that is, no noticable reduction in Google's capability of reading process memory of your instance of Signal) for any of the current Signal users (which are implicitly Google Android users, although a some instances may be non-Google + google services manually patched in). The primary benefit is that some people that cannot currently run Signal due to the dependency can join while maintaining the non-Googliness of their system.