Insular doesn't itself prevent apps from calling home, it just isolates them so that they cannot access any files or other apps outside of the work profile.

But more generally, there's nothing to indicate that they forbid apps that disable call-home schemes and there's no mechanism forcing app developers to add a phone-home-to-Google feature. The closest thing would be their Play Integrity scheme, but it still requires the app developer to decide that their app should only run on unmodified ROMs with Google services.

I mean, Signal, Wire, the Proton suite, and Mullvad VPN are also on the Play Store and it would be big news if Google directly bugged those apps on condition of being available on the Play Store. If you are really worried, some apps like Signal also have reproducible builds so you can audit the code and make sure nobody's injected extra code into your download.