Ex-Goldman person here. To the best of my knowledge, RabbitMQ was used in spots but not where reliability was critical. Instead the main message brokers were IBM MQ and TIBCO. RabbitMQ would certainly lose messages in the event of a crash, and I'm not sure it would have been used for the main message bus given the rate of events. Additionally, Erlang was used for SecDB queries quite heavily. This was the bread-and-butter of the firm (https://github.com/saleyn/secdb)
Erm... https://github.com/saleyn/secdb
Written in Erlang with a C driver for low level stuff.
Author is Serge Aleynikov. Ex-GS employee sued in multiple courts over many years by GS.
But yeah, not "officially known" as in they released, but there is probably some association there. Just a guess ;-)