That will be found out, once the phone is released.
Right now they are still in the process of developing and tuning the software in some ways.
For example take a look at this statement in th thread on camera modules:
Judging by the pictures on the pre-order page, there is no jack input on any side. And I can’t see one on the pictures of the disassembled phone as well.
Seems consequential to me, since they decided to drop this feature with the FP4 and developed new wireless headphones.
The specs list also mentions the USB port for connecting “audio amplifiers”.
In all: I, unfortunately, would not expect any jack input at all.