I don't think you are quite talking about the same kind of design here.
You are talking about very high level choices. (Do we bundle a charger with every new phone? does the phone have a jack?) Those are not really good examples where familiarity is important.
The argument about the importance of familiarity is in the UX paradigm of the phone. Think about the task of pairing a phone with a wifi network. You usually do that by unlocking the phone, finding the settings (which is most likely under an icon resembling a gear, or a spanner, even though neither of those things had anything to do with setting up wifi). Then inside the settings you have a long list of things you can set, you can move between them by dragging the screen up and down. You find the menu item for wifi (probably has a wifi logo, or radio waves icon) you click that. Then you see something where you can turn the wifi radio on or off, and you see a list of SSID's you can join. You click the one you want to join, and it asks you for the password associated with the network. Usually you can tap the password field and an on-screen keyboard appears where you can type the password in.
This is by and far the way to connect to a wifi on any modern smart phones. This is the "familiar".
To better illustrate what "lack of familiarity" would mean imagine a phone where instead of finding the wifi settings in a "settings" menu you can connect to a new wifi in the maps app. Why? Wifi networks are location dependent, so why not? These designers decided that wifi networks appear as small colourful dots on the map. Then imagine if after tapping your selection from the list of SSID's you would need to push a button on the side of the phone to "accept" it. Otherwise it won't connect. Then imagine that instead of showing you an on-screen keyboard to type in the password you need to morse-code tap the password in by tapping the back of the phone. The phone would indicate this to you by showing an icon of a drum kit.
This is what "lack of familiarity" would look like. Clearly this imaginary phone would be very hard to use, and the users would reward the manufacturer's creative thinking with a lot of returns and complaints.
