They generally had traders bribing their way backwards and forwards to China all the time and at least a steady trickle of foreign tourists, so it seemed unlike

They generally had traders bribing their way backwards and forwards to China all the time and at least a steady trickle of foreign tourists, so it seemed unlikely they wouldn't get it. But it does say in the article they had shut their border in the pandemic so maybe they clamped down hard on unofficial China visits. I hear it's easier to get over to China in the winter as the river separating the countries freezes over. Maybe traders have been making it over in more recent months and brought the latest covid back.