The communications system is not novel. It's GSM-R, which is good old 2G cellular with some special railroad features. Both voice comms and signalling run over that system. Since both went out, the comm system must have failed.
Industrial grade communication systems tend to be very well behaved in terms of fault detection and management. I'd be very surprised if the whole whack-a-mole dynamic described in the post was a failure mode of GSM-R system per se.
Train drivers lost their voice connection to their control centers.