Most FM receivers nowadays rely on creating a signal of a specific frequency that interferes with the desired on-dial frequency, this is called an intermediate frequency. Then the actual audio signal is analogous to the changes on that IF.
This technique is known as superheterodyne, and Technology Connections has a wonderful video explaining it better than I can.
I have a genuine question, what's to gain from this? I could half-understand it if they were going to re-allocate the 88-108 MHz block, but that doesn't seem to be the case.
I could also understand why such an action would be taken if that meant that they could pack more stations in the same spectrum, but considering that Switzerland is a relatively small country, so is there really a market? Even if considering multiple languages per niche.
I guess a case could be made for power savings by virtue of (assuming local topography allows) lower power transmitters or by multiplexing various stations on the same transmitter.
On a personal level, I'm not entirely sure how I feel about all forms of analog broadcasting being slowly phased out. The tinkerer in me likes the idea of being capable of constructing an information receiving device in an almost "survivalist" manner, but if this trend continues and analog FM really goes the way of the dodo, then I surmise that DAB (or whichever local flavor is chosen) will become easily and cheaply available, which makes my gut feeling a moot point anyway.
I don't know, I just don't like the idea of needing a processor to receive broadcast audio, and I can't quite put my finger on why.