I was with you on the outboard DAC.
Getting rid of the analog port obsoletes all analog headphones released, ever. Drag.
But - allowing an outboard wired DAC is a Good Thing.
Right now, several popular phone models have DAC and analog output stages that are excellent but the presentation is completely marred by replay gain and digital volume control, among other processing.
If Apple puts a big fat "ZERO SUM" option somewhere in iOS that forces software out to be forwarded to the jack unimpeded, I would be completely on board. Death to the analog port.