While I'm with you and won't be buying one for reasons beyond the 3.5mm jack (but that would be a deal breaker if I was on the fence), I'll be
more surprised if the removal of that feature stops scores of people lining up to get the latest phone (along with a new set of over-priced headphones).
At the end of the day, it's "give up the 3.5mm jack" or "don't get the latest iPhone" and I'll wager that they'll have no problem generating lines filled with people that just have to have the iPhone 7 because...Apple! Apple has a near-religious following. I got a kick out of a friend of mine who upgraded on release when they ditched the 30-pin connector. He'd recently purchased an alarm clock, an add-on for his home stereo and had already owned several other 30-pin reliant bits. They were on eBay the following week. Out of the non-techies I know that purchased the iPhone 6, none of them could tell what, specifically, they were getting over their existing iPhone 5S (that's a grand-anecdotal-total of 3 folks, though).
If there is resistance on this release due to there not being enough compelling features, that resistance will eventually give way. Many people are so wired in to Apple's products that lock-in will win. Maybe they'll wait until the 8. But eventually Apple will be making money on sales of ear buds with Apple-only connections and will benefit from yet another component that locks them into their platform. And the folks who spend $200 on supposedly high-end ear phones[0] will now feel even more compelled to stick with Apple's product line.
I'm biased and this is a little overly cynical. I've never owned an iPhone and the two Apple devices I've ever owned: an iPad that belongs to my wife and an iMac that I use as a display (target display mode) because, at the time, it was a little less than a comparable "screen only" device with similar specifications (and it was physically prettier, to boot). I've not logged into it, directly, in two years and don't really get the appeal of OSX.
[0] I've never understood this. I have a pair of 25 year old studio headphones (AKG, 1/4" jack, big, over-the-ear with a very long cord). I needed them due to equipment and was sicked that they ran 10 times the price of a pair of solid headphones, but I was amazed by the quality they produced. I didn't want to buy these, but after 25 years of heavy use (and the manufacturer still makes the model I purchased), I can't say I feel bad about the price. The Beats/Bose headphones? I can't tell the difference between them and a pair of $30 active noise cancelling headphones I purchased from Big Lots. Granted, I can't plug my AKGs into a phone even with an adapter -- they're too quiet.