I do think that Apple wants to eventually move to a compelely "portless" phone. The headphone jack was the first big step towards that direction and I wouldn't be surprized if they eventually remove the charging port as well, in favor of magsafe-only charging. Sounds even more plausible now that they can't monopolize the sales of lightning cables since the introduction of USB-C.
Well, I'll soften that a bit. Not having a headphone jack is something that doesn't work well for me, personally. Bluetooth is not a good replacement for it.
I don't think they can really claim revealed preferences because Apple never sold a product that was identical except for the headphone jack and battery life. Of course people are going to buy the better new one. Apple could have just sold two versions, one without the jack, with a bigger battery, and one without, and a smaller battery. That would be massively more expensive for Apple to do, but it's not like Apple isn't swimming in ridiculously giant piles of money.
The rest of the market largely followed suit though, despite the fact that at times Google tried to specifically market a 3.5mm jack as a feature. If the presence of a headphone jack was really critical, wouldn't some premium handset maker have capitalized on it?
Yes and I think in the future, we would have phones where all buttons and ports are removed. Volume control and screen on/off would be automated based on context and charging and data transfer would be wireless.
My take is that I was cranky about it at first, but now that i've finally lost all of my legacy wired Apple earbuds I'm happy to have the 1-2% extra battery.