These 7 nm chips are probably just prototypes. It's too early to see if these will be ready for mass production.
That not the significance of this news. The significance is China achieved 7nm using no US equipment or parts. US has the EUV light source technology to make even 2nm, but they don't have the technique so their poster boy Intel can only make 10nm and has to go source 7nm/5nm chips from Asia. China don't got no EUV light source technology, but they already mastered/mastering the 7nm node using home grown equipment! It only matter of time China mass produces 7nm.