Answer revealed! According to the official description, AJX002 is a new unmanned mine-laying system.
According to the official voice-over:
“自主巡弋,出击深蓝!海上无人作战方队开过来了。受阅的新型无人潜航器、无人艇、无人布雷系统,具备隐蔽布放封锁、自主探测识别、集群组网攻击等作战能力,是海上作战的奇兵利器。”
“Autonomous patrols, striking into the deep blue! The unmanned maritime combat formation is approaching. On parade are new unmanned underwater vehicles (UUVs), unmanned surface vessels (USVs), and unmanned mine-laying systems, which feature covert emplacement for blockade, autonomous detection and identification, and swarm-networked attacks—a surprise force and potent asset in maritime operations.”