So it is simply a change in what it is called - so unless there is no longer any direct link (as you claim) at all with the price of fuel it is still very much a fuel surcharge!
Or will BA try and con everyone as per your attempt to and state it is now a "carrier surcharge" with no link to the cost of fuel therefore no need to be reduced in line with the falling oil price?
Although somehow I sense if fuel rockets again, the story will change back to being there is an influence in YQ with the cost of fuel therefore it will go up.
Or am I just being cynical?
Well, they changed the name to "carrier surcharge" EXACTLY because they did not lower it when the fuel prices dropped. So it is now some accounting gimmick used to their advantage.
You can hope EC introduces some new legislation preventing it. The same way they took care of the credit card transaction charges, roaming etc, it may be on the list.
Here in Brazil there is no YQ added to tickets originating from Brazil. There are only fare and government taxes. That results in low redemption costs (although BA tries to scam these too). It also has the disadvantage that I've several times seen prices Europe-Brazil-Europe as low as 300 EUR, but Brazil-Europe-Brazil never goes bellow 1000 EUR.