Re: Do as we say, not as we do
To be honest, as long as WhatsApp is using the Signal protocol, this is better than most of the other options: end-to-end encryption, no data stored on servers. This is why Facebook Meta is desperate to introduce advertisting on WhatsApp.
But there's lots of metadata such as location that is leaking and that's probably worse at a forces base. Remember the Strava incident? And the US and others are probably pulling similar stunts on Russian military personnel.