A lot of the "omg no headphone jack" griping is, well, overblown.
I won't deny that it's less convenient, and sometimes arbitrary. But it's always amusing when people act as if it's the end of the world, and they can't imagine how anyone can live with a dongle or buying Bluetooth headphones. Folks... it's not that bad. More often than not, you can attach the adapter to your favorite set of earbuds and forget about it. The big issue is that you can't charge while listening to wired audio unless you buy another adapter.
And no, it's not as simple as claiming that company X or Y is greedy. In the iPhone 7's case, for example, that space does get used for other things (the advanced haptics, a slightly larger battery, even a barometer). If you're going to be cynical, one theory I've heard is that Apple is removing the jack on the 7 so that it's not a distraction when the 8 comes without any room for that port. Get the complaining out of the way now so that everyone focuses on the major redesign's positive features.
And to answer the original question: yeah, it's probably going to be a thing. I don't know that the vast majority of phone makers will follow suit, but there are reports that even Samsung might ditch the headphone jack. You may have to settle for a phone you wouldn't otherwise prefer simply to get that jack.