There just is no conflict between water-proofnesss, repairablity and having a headphone jack.
Water-proofness/resistance and a headphone jack does not collide at all. There are many devices that proof that. For repairability, I also do not see how this might conflict with the other goals, as quite some devices had headphone jacks that were easy to swap. Look at how the framework laptop puts them on a small audio board for example, the same had been done in phones.
So again, this is just my recollection, but glueing parts shut sounds like it should help prevent water getting into the device. So if you can't do that, I assume you get closer to not getting the certification, and then adding another hole in the device might push it over the edge?
I do remember they explicitly addressed this in the FP4 launch, so it wasn't for lack of want.
Look at https://www.youtube.com/watch?v=-_S6JaLvDck. It's a teardown of the Xperia 1 II. It shows how easy the audio jack can be removed there. The phone is certified as IP65/IP68.
The phone itself is glued, but the jack does not seem to be. It likely works with pressure and might have a gasket seal - which is not surprising if you look at how watches do it.
But I think you are right - they said something like that when the FP4 came out. But that phone is a matter of principle anyway. If it is possible to get the phone with an audio jack in a good state, but the certification process is broken, then they should not certify it (and publicly attack the certifier). The Sony phone shows it can be done on a technical level, which is what matters.
I was indeed not talking about glueing the jack, but about the rest of the phone. Not doing that will presumably lower your rating, and then adding a jack would lower it even more - and I'm guessing that would lower it beneath the water-resistant certification threshold.
Water-proofness/resistance and a headphone jack does not collide at all. There are many devices that proof that. For repairability, I also do not see how this might conflict with the other goals, as quite some devices had headphone jacks that were easy to swap. Look at how the framework laptop puts them on a small audio board for example, the same had been done in phones.