just to clear this up, arcee is not in any way confirmed dead. two of the three bike bots take direct hits in the final battle, with nothing seen of the results. sideswipe gets exactly the same treatment. ironhide ends up worse - after being hit, he is seen with a blazing hole in his chest, struggling to get away from the airstrike. arcee is no more dead than sideswipe or ironhide, and jetfire struggles on for a long time with half of his body missing, so no reason why the others couldn't.