User blog comment:Damac1214/Black Ops II - DLC 5 Rumors surface/@comment-180.252.68.171-20130624094026/@comment-173.58.181.27-20130625073206

The reason 2025 tech is present in 1996 is the same as why 1968 tech is present in the WAW zombie maps: The Demonic Announcer simply goes forward in time, and transports the materials back in time, and vice versa, hence the weapons.