I think that's why so many try going across the Himalayas. IIRC Calbear has stated in the past unless someone is in the senior leadership or lives on an orchard they hadn't seen a fruit before. Instead they get dehydrated fruit and other stuff that can be called food but no one wants to eat unless its to keep you alive and there are no other choices.
Plus areas around Hong Kong and others border areas is a 12 mile or so deep entrenched zone that makes Berlin Wall look like a playground and its a papers please zone.
My guess is the Cabel's grip on China isn't as secure as they would like but they are able to walk that fine line. Basically I have to guess they are one harvest away from starting WWIV
But considering that every nation outside of China, except Soviet Russia, hates the cabal, wouldn't more Chinese be able to flee?