The risk with not giving your why
Apple have many loyal, read die-hard, customers who will ALWAYS buy their product and making a big change to an already loved product was never going to rock their loyalty. BUT the reasoning behind Apple making this change which they gave in their marketing was, in my opinion, a marketing fail.
They didn't explain the benefits (ie better sound quality, more efficient technology, making a better product for the customer, healthier way to listen; whatever it may be) they just explained that it was a move born out of courage. They were daring to do something different and break the mould. Does that win new customers? We are brave so you should buy from us?
I dont think so. As I said, loyal customers probably won't be turned off from the iPhone 7 based on this one change but anyone sitting on the fence over which phone to choose once their upgrade is due, might. There wasn't one benefit to the user of choosing a phone without a headphone jack(quite the opposite) and I think this will have hurt their new sales income more than any other of their product releases.
A great product beats everything else.
That being said, the iPhone is a revolutionary product whose reputation precedes itself. Because of this, how many people were really listening to the marketing? We are a generation of people who are already sold based on our previous experience. If you have a product as reputable as the iPhone, does your marketing message really matter?
COURAGE really does work.
I have no doubt that, much as the lack of headphone jack has caused a small inconvenience to many customers, within five years it'll be a standard feature on ALL handsets. I'm sure that headphone sales will now start to reinvent themselves based on this change which will lead to all phone handsets following suit.
Watch this space!