Not one minute after the call ends my boss who "wasn't listening in" called me to reassure me that my job was secure. Since I was the only one of our team in the entire state, I was reasonably certain that was aready the case.
I quietly let some of the team who I trusted know that the anonymous calls were anything but.
I could have left then but I was 60+ years old and desided to just ride it out until retirement. They re-orged shortly after and I ended up with a new boss so it worked out for me anyway.