Otherwise the evacuation of citizens would have been handled better as you said. The US claims that China told Russia to postpone actions against Ukraine until after the Olympics, but this is probably either completely fabricated or else the PRC greatly underestimated the scale of the Russian military plans.

Incidentally, I am surprised that the US had such knowledge of the plans, which indicates that US intelligence has infiltrated Russia much more thoroughly than their Chinese counterparts. I am even more surprised that they would release such information to the public just before the invasion, because it obviously could compromise their intelligence sources.