Earlier quoted context omitted.
While true, China's threat has been going on for a long time and they've been running repeated exercises on how to do it, how to take US warships out, etc. Additionally, US support for taking Greenland is virtually zero. Chinese support for taking Taiwan is frighteningly high.
China is not an irrational actor. They know that the most effective way to take Taiwan is slowly, through soft power and political subterfuge. There is no need or advantage to a full frontal assault.
The person at the top of the chain was asking why everyone is preparing for war. This behavior from China is why. It predates any of the Greenland Trump idiocy, too.