It looks like it will be. Jetbug's left arm shows fairly clearly that there are square "brackets" (I really don't know what to call them) on either side of the ball joint, which probably push up against flat surfaces on the inside of the armor pieces to prevent them from turning or wiggling.
Though there's one thing that bugs me; Stormer, Surge, and Evo's lower left arm pieces seem to be shorter than the other lower arm piece and don't have the middle ball joint, though overall their left arms appear to be the same length as the others'. I can't tell if this is just an illusion or if it's actually the case.
Because an even shorter arm piece would be twice as much <3.
(Breez and Nex's left arms look like the longer piece, and I can't see Furno's for obvious reasons.)