Boeing is the easiest and perfect pick as an unrealible entity company.
1.) Boeing already had safety issues with their planes. And there is some indication it was a deliberate design flaw. So that is a technical reason.
2.) They expect a US 1.3T(T as in trillion) plane sales from China over the next two decades. Why should China allow
this sales to proceed with all that anti-China actions from the US. With all that money, it is impossible for COMAC
not to catch up to Boeing/Airbus standards.
3.) International air travel is grounded anyway. And probably may not recover to maybe 2 to 3 years.
There is no substantial effect in China economy if Boeing orders will be indefinitely suspended.
4.) If indefinitely suspended, that will have a profound knock off effect in Boeing supply chains which
China does not benefit anyway. There are no plane parts from China supplying Boeing.
Airline industry and Boeing not exempted are suffering from the pandemic.
So just like in physical combat, you kick the wounds of the enemy while they are limping to inflict maximum pain.
Here is what Global Times has to say with this unreliable entity list
" In May, a source close to the Chinese government told the Global Times that China was ready to put US companies on its Unreliable Entity List, impose restrictions or probe US companies like Qualcomm, Cisco and Apple, and suspend airplane purchases from Boeing, in response to US threats to cut off foreign chip supplies to Huawei. "