The source is not reliable! Unless the Chinese government makes an announcement or at the very least someone from China says something, this is an unreliable statement by a US based investment company!

These guys are basically making a guess and the media is creating a clickbait out of it, hence your title as well

I doubt China is about to dump US treasury bonds this quickly. It is a tool they have in their hands to really shock the US economy and dump it suddenly. They are unlikely to spend that card at this stage when all that has happened was Trump threatening them a little.
Besides they've already retaliated and we are seeing its consequences in US economy already...