I believe that’s no longer true. That is, there are now orbiting satellites that use GPS in a client capacity for whatever reason.

I’m pretty sure I recall a paper I saw on the subject discussing how the Earth centered inertial frame can’t just be used unmodified.

Those satellites have GPS receivers, but they don't "communicate with" a GPS system (which implies they are transmitting to the GPS system).

I'm sure there are some Russian or Chinese satellites that can disrupt GPS satellites, maybe that would be considered to be a system that can "communicate with".