The article is poorly worded. People weren’t evacuated from Vladivostok. They were evacuated from the Korean border which is about 150 miles from Vladisvostok. The civil defense agency handling the evacuation is location in Vladisvostok.
They’re clearing out the border village of Khasan Xacah. Probably to convert it to a supply depot. They moved amphibious-capable supply units to the NK border several months ago. Imo the Russians anticipate the Freedom Bridge into NK (just outside the village) may not last long in a shooting war. The amphibious supply units indicate the Russians intend to continue supply operations into NK following the loss of the bridge.