I can provide one side effect of this change: I won't start collecting miles on Emirates. Being based out of CDG, I will need to go to Dubai on a semi regular basis. However, I calculated that it will take me NINE roundtrips between Paris and Dubai in Saver fare in order to qualify for the basic SILVER status, and 17 to qualify for Gold.

The system is fine if you are based in Dubai and so use Emirates to fly to most locations, but if you are not based in Dubai, and since Emirates is not part of an alliance, it make no sense for me to put my miles there. I'll take them on United and forgo the useless tier miles.