Nokia should be in politics as they have a knack for giving "non-answers" and changing the subject. Case in point, the official line from Nokia with regard to the 928 is simply:
"The Nokia Lumia 928 does not have the hardware required for FMradio, but Nokia Lumia Amber brings the new Nokia Smart Camera."
There is no disputing that the phone is equipped with Snapdragon S4 processor and MSM8960 chipset. FM radio, along with GPS and Bluetooth is iintegrated into the modem subsystem of the chipset so it is not a lack of a circuitry with regard to FM tuning. The best information regarding the disconnect is from paulheu in the Nokia discussions at this link:
FM tuner for Lumia 928 - Nokia Support Discussions
Complete specs for the Nokia 928 can be found at
Nokia Lumia 928 - Full phone specifications