Swedish Steve
The end result may be as you describe, ie more people taking flight plan fuel more often. You have probably despatched me on several occasions over those years.
The reason for the change however has nothing whatsoever to do with the league tables, the vast majority of pilots never consult them.
It is much more to do with 2 other factors:
1. Education. A lot of effort has been put into explaining the rationale behind the fuel policy.
2. The old SWORD planning system did not use Statistical Contingency Fuel. It used a standard 15 minutes or 5% type of number. The new CIRRUS system uses Stat,Cont,Fuel, which can quite often give you 25 minutes contingency inbound to LHR - a figure that most of us can see as being sensible. Cirrus plans use actual reunways in use, whereas SWORD used normal dep runway and longest likely approach routing. Current aircraft FM(G)C's are also much more sophisticated than older versions.
So what I'm saying is that you shouldn't assign a reason to a perceived change in customer practice without knowing more detail.