It would be really cool to see the XM1A3 replaced with the new Abrams X.
The Abrams X features a Hybrid Diesel engine, and a unmanned turret.
The Abrams X also is lighter, which makes it more maneuverable than the M1A2 (All varients)
The Abrams X would look much more up to par with the other Tier 10's in it's class