Expected and necessary move. Maybe a solution, to avoid players just doing this mission and nothing else, would be to set more requirements to be able to do the mission. For example, doing a minimum number of daily missions, having bought X packs in the last few days... What is clear is that the current system is not viable in the medium term.
Otherwise, thanks for the hard work you are doing.
they did make a change a few months ago to require an increasing number of fans each time you run the mission. Not sure what else the could do to keep it balanced, or what the motivation is. They are saying they are re-evaluating the card, and probably the mission, so we'll just have to see how things turn out.