When does a form factor die? When Adele shut her flip phone in "Hello," it was supposed to be a symbol of the past. Phones with physical QWERTY keyboards also seem to have mostly bitten the dust. Yes, you can still pick up inexpensive flip phones and the keyboarded BlackBerry Priv, but they're not considered significant parts of the market.

Now we can ask the question about smaller smartphones, too, and we may see Apple offer up the answer early next year. According to various not-terribly-reliable sources cited in BGR, Apple intends to replace the iPhone 5c with a small, A9-powered "6c" or "7c" in January. Smartphones got bigger and bigger for a while because people wanted bigger windows to the Internet. But ultimately, they're handheld and pocketable devices, so for now we seem to have reached an uneasy equilibrium around 5.7-inch phablets being the largest devices people want to carry around. (There have been 6-inch phones, but they haven't been too successful. They're just too big.)

As phones get bigger, I've been hearing complaints from many readers and friends—primarily women in urban areas, who want to use their phones in one, smaller-sized hand—that current premium Android phones are just too big. Those people flock to Apple's iPhone 6 line, which at 2.64 inches is the narrowest premium smartphone out there right now.

(Tangent: when people talk about screen sizes and comfort, they're never really talking about screen sizes. They're talking about the narrowness of the phones, because that controls what you can reach with your thumb.)

Americans have trouble thinking of smaller things as high quality. We want bigger cars, houses, and phones. So it's not surprising that analysis of Apple's potential new 4-inch iPhone centers around the idea of it being a "cheap" or "low-cost" option, which in the iPhone world probably means $499.

A $499 iPhone would indeed create pressure on a burgeoning new category of competing semi-premium, mid-sized smartphones, probably limiting them to $400 or lower. That puts the $379 Google Nexus 5X and $249 OnePlus X in a decent position, but creates trouble for the $499 HTC One A9 and especially the $549 Microsoft Lumia 950.

But more than a pricing game, I'm interested in seeing this as a real test to see if there's still a market for high-quality, smaller smartphones. While there are still a whole bunch of 4 to 4.5-inch smartphones in the market—especially globally—they're generally super cheap, and bought because of price rather than quality.

An Apple phone changes that equation. Once you get to $500, it's not that much of a jump to get to $549 for an unlocked 4.7-inch iPhone 6, so at least some of the buyers of these iPhone 6c/7c units will be getting them because they want something that easily fits in one hand, not just because they want to save dough.

Kantar chief of research Carolina Milanesi disagrees. "I still do not believe people want 4" iPhones; they want the price that those 4" iPhones are sold at," she told me on Twitter. Creative Strategies analyst Ben Bajarin chimed in, "The market is moving away from smaller devices," and added that price-sensitive customers are more likely to buy a 5-inch, $200 Android phone.

So that sets the stage. I welcome the iPhone 6c/7c, especially if it appears in January as predicted. It'll show whether a small, premium smartphone is actually something people want—or whether smaller smartphones are in fact going the way of Adele's flip.