They could have retired the system after the war's "end," but it is tough to keep track of the thousands of recruits now stuck on AG and the Block Yards. Remember standard rockets can only go between preset destinations, prior to hacking them. The Nexus Force is too careless to organize a massive status upgrade for the Limiteds, especially with the AG front being a constant sore spot that leaving them there remains strategically preferable, however all new recruits after the Faction War are no longer subject to this. This is parallel to, following LU's closure, everyone on the new servers can do whatever they want.