Slip of the pen, we know you meant Khz really. However, for some years now (probably more than 10 IIRC) the CAA have been assigning 12.5Khz channels - which seems to have slipped under your radar.
I'm a bit curious about all of this, I know that all sorts of people have been pushing 8.33Khz for a few years now "because there were too many users needing space", which was the original driver for 12.5khz channels. If this is true, how is OfCom(ic)'s price mechanism going to help us here?
It is certainly true that there are still many GA aircraft out there with 25Khz radios and there have been the odd sticky moment with those 25Khz radios unintentionally causing problems near stations using the "odd" half channel. Even though these "odd" half channels are chosen to minimise issues of this kind (bearing in mind that VHF LoS @ 4000' is quite a long way). As a result the number of available channels is many fewer that one might have at first thought.
Lord knows how they are going to slot in 8.33Khz channels. I suspect diminishing returns here.How on earth they intend to weave 8.33Khz radios into the existing mix of legacy kit, and how may real extra channels they get as a result should be interesting. Especially as this is all DSB AM.
Anyway, bearing in mind (as I suspect OfComic isn't) the LoS issues for aircraft, and a long standing dearth of *safe* free channels as a result, it seems to me the that is really is a money making (and/or power grab from the CAA) scheme by OfComic. I suspect the CAA are not happy (even if they think they will get a rake off - as they issue the licenses).