I think what they are going for is purchase with cash a "fake" F ticket in a name that is not yours in order to take that seat out of inventory. Then just before you check in cancel it, thereby putting that seat back into inventory and opening it for an upgrade. I suppose there is nothing in theory from stopping you from doing this, but if Emirates catches on that could be an issue for you, and could ruin the current generous upgrade policy for everyone else if they feel people are gaming the policy.
Agreed... perhaps mods should even delete parts of this thread to avoid people getting any ideas, the policy is very generous, and "hacks" from this forum ends up on the credit card-shiller blogs all the time.
This policy is the only reason I've gotten to fly EK F.. except for the 50% off miles sale they did in Q1 2017.