I think the name was a play on both "Ericsson Language" and the name of Agner Krarup Erlang, who pioneered queuing theory (before it was known as such) to address the fundamental question of inter-exchange capacity planning.
The unit "erlang", for "1 busy circuit/resource" is named in honor of that research.
https://en.m.wikipedia.org/wiki/Agner_Krarup_Erlang