Are you sure you're not thinking of the 2008 Uber Cup? KOR threw their group matches there, but they took advantage of the format. The 2009 Sudirman Cup didn't even have Quarterfinals, it only had Semifinals. Korea won its group and faced INA (the second placed team in the other group) in the SF. You couldn't really take advantage of the format in the last Sudirman Cup, since there were only two groups and the SF would be winner A vs. runner-up B and winner B vs. runner-up A (in this case, KOR vs. INA and CHN vs. MAS).