Here's an interesting one:

I've just received a phone call from BA informing me that there will be no F cabin on my flight from UVF in March 2015, although it is there on the day before and day after. I was offered a complete refund (Taxes, Avios, 2-4-1), a downgrade to CW plus Avios refund, or a switch to another date, irrespective of reward availability ^.

What are the possible reasons? The ones I can think of are:
a) BA know that the loading for that flight will be so low (i.e. just my wife and I) that they have decided to close the F cabin;
b) That they know that they will have to change the aircraft to a three class for that day due to a technical issue;
c) The entire cabin has been nabbed by VIPs.

With a) and b) being so unlikely this far in advance I'm going for c).

Any other suggestions?