As the second richest person in China, he's in a position to know the minds and influence the opinions of party leadership. I absolutely do not take his statement with a grain of salt. I take it as a threat.
Lol, did you even read the article? He used it during your typical anodyne corporate speech at some event in Australia. This sentiment is as old as trade itself - "If goods don't cross borders, armies do." Ma was speaking to the unifying power of globalization and trade, not some ultimatum he was giving the Trump administration.
[1]http://www.cnbc.com/2017/01/29/us-china-war-increasingly-a-r...
https://www.theguardian.com/us-news/2017/feb/02/steve-bannon...
if it comes to real armed conflict, everybody lost, except perhaps a few elite types.