?more cans??
Nope, but they did manage to squirt more fuel into the existing cans. This has the effect of raising the turbine inlet temp and getting it to squeeze in a higher amount of air by also increasing normal operating RPM a tad. More air = more thrust, more temp can only be tolerated by higher temp materials in the turbine of sophisticated cooling air.
Re: EPR vs RPM vs Thrust. Well EPR just refers to the pressure differential that make up thrust. RPM typically directly relates to these pressures, but not always. I seen either EPR or RPM give off false values for thrust when the engine is operated in a damaged mode, however EPR is typically more reliable.