In my opinion I think the MTA told Bombardier to hold on from sending the other sets for smart reasons because just in case they need to fix anything that's they wrong with the 3010-3014 so they can quickly modify the oncoming car so in turn they can have the other cars rapidly coming in and mostly do a burn-in test and start putting those cars in service lol . Because I find it odd to start testing the 1st 5 without the other sets. Even though it has happen before but still the mind does wonder lol