Not necessarily an equipment change but year before last I flew to Nice on the Sunday afternoon of the Monaco Gran Prix. The plane flew out with an almost empty CE cabin of half the plane - the biggest id ever seen. The rest of the plane was full. Clearly the economics of bringing back lots of CE passengers outweighed the loss of Y revenue on the way out (and given that a return in CE for May half term was £1k vs £150 for ET you can see why!)