It is possible, at least in theory if not in practice already, that the Google dialer and messaging apps could relay some information to the Google Play Services/Store (or other Google apps) by way of Android's inter-process communication (IPC). This would really only be a privacy concern if those other apps had network access.
Technically, IPC is possible among all Android apps, but I'm generally more concerned when trying to isolate one app, and a secondary app made by the same developer has less restrictive permissions. My feeling is that unwanted IPC is more likely to occur among apps from the same developer.
For example, I use Gboard without network permissions, but I would not trust that my Gboard data is 100% private if I also had Play Services installed with network permission allowed.
Since the Play Services and Store apps are widely used by apps as a conduit for communication, telemetry, advertising, and other services, I made the decision to not use apps that rely on them.