This is Absolutely justified. I too am a little surprised that China is the first country to do this, but politics aside, this is a brand new "state of the art" 737 that's had 2 crashes in the same phase of flight literally months apart. Both brand new aircraft fresh off the production line. All new aircaft go through teething problems but this problem has cost 340 lives.
While we don't know the cause at the present time, it is extremely concerning.
I mean, as a pilot how would you honestly feel walking down the aerobridge getting on one of these things? No thanks.