Not every iPhone is created equal. Dual-sourcing parts is fairly common, especially in the mobile space. Samsung, for instance, is known to have separate models of the same phone, with some using its own parts, and others using third-party components. Apple has even designed separate versions of the same SoC in the past, to fabricate them at different locations and on different process technologies.
This case is more simple than that, though. Depending on the specific iPhone 7 that you get, which mostly varies by region and carrier, but also apparently between Plus and regular, you will either get a Qualcomm Snapdragon X12 modem, or you will get an Intel XMM 7360 modem. The ratio between these two parts, all markets considered, doesn't seem to have been announced yet, but old rumors claim about 70:30, Qualcomm-to-Intel. Still, Apple is a pretty big customer, so I'm hoping that both Intel and Qualcomm are moving enough to (Update: Sigh… input fail… original article cut off here. The rest of the sentence, after this update, was added a couple hours later.) be worthwhile for both parties.