Aren't that expensive? You want to buy me an iPhone 8+ when they come out. Now that the lie of 'subsidized phones' is dead, I'm imagining a lot more people choosing to stick with their old phones.
The (rumored) $1,200-$1,500 "8+" (I think it won't have that name) won't be the only new iPhone model. There will undoubtedly be a 7s and 7s Plus (by those or other names) as well, hitting the same price points as usual. As with today's SE vs. the 7/7 Plus, the higher-priced model with all the bells and whistles will make the lower-priced models seem like a good (or even great) value, and everyone who's been waiting to upgrade will buy whichever model they can afford.
And if people use their phones longer than they have in the past, that's perfectly fine in my book. I've always been that way (I went from iPhone 4 to iPhone 6 in a single jump, used my original iPad for over five years. I recently replaced the battery in my iPhone 6 and it's working great - while I expect I will get another iPhone, likely early next year after the new model dust has settled, I'm in no particular rush.
Extended use/re-use/repair is generally better than recycling, recycling is far better than dropping it in the trash.
Here's the thing... While every little bit counts, the amount of resources that go into our little smartphones is small compared to the resources that go into a laptop, desktop, or car, or even a Sony Walkman, back in its day. Keeping a Mac for one extra year has greater impact than keeping several iPhones running for two extra years each. I recycle far more household aluminum, glass, plastic and paper in a week (and discard more non-recyclable plastic) than went into the iPhone I've been using for over 2.5 years, and I'm fairly conscious about avoiding things like excess packaging.
As an enterprise Apple has a large footprint, so its environmental practices are certainly meaningful. However, in the big scheme of things there are much larger fish to fry. While the discussion is valuable, in the end "report cards" of this sort strike me as so much clickbait, too little perspective. Apple has a huge, attention-getting name, and the company makes a point of how environmentally friendly it tries to be. A headline about a "dirtier" company would get a big yawn; "Sure, tell us something we don't know!" With Apple, they get to point the hypocrisy finger; much better bang for their PR buck.