It is the risk of a new, virulent variant that concerns the public health medics. China unlocked is a giant Petrie dish so the chance of a new variant causing serious infections is higher than it was before they unlocked. Xi only unlocked because of public disturbances. If Chinese streets had remained quiet I doubt he would have abandoned their zero Covid policy so quickly.
Are they not planning to test waste water from planes coming from China to help discover if there are new variants? I read that somewhere this week, but unfortunately can't remember where.
The new rules for the testing of people arriving to the UK from China is a complete waste of time and money. This scheme has got more holes in it than a colander. Determined travellers can enter via other countries and do we trust the Chinese authorities to test accurately? Anyone testing positive on arrival after a voluntary test will not have to quarantine. It seems we never learn.