I believe that some of the Audionote (uk) phono stages are transformer coupled (referred to as balanced output). These are truly cost-is-no-object designs, so there must be something good about using transformers for the output. Audionote uses transformers for the output of their DACs as well.
I suppose the other way to reduce output impedance, aside from CJ's use of parallel output tubes, would be a cathode follower, but, there are enemies of that design choice too.