Originally Posted by
EKfreak
I was looking at purchasing a economy flex and upgrading to business but none available for that flight - well all of them really haha.
That wouldn't have been a solution. Economy Flex tickets do not upgrade to Business Flex Rewards. Upgrades from Economy Saver, Flex or Flex Plus always go into Business Saver Rewards category, the aforementioned "D" bucket. The only difference is the number of miles required to upgrade, and Savers not being upgradeable until check in time.
ETA: Reading your post again, I'm not sure that's what you meant, but I'll leave this here anyway in case it helps others.