[Turing_Machine]

"There is no use case for the headphone jack that can't be better handled by the lightening connector or bluetooth."

Using a quality external microphone.

[20yrs_no_equity]

Audio can go both ways over lightening.

[Turing_Machine]

Nope. The Lightning port is a purely digital connector. Using an external analog microphone would require some kind of external ADC (i.e., one more bit of kit to misplace).