I didn't read much into that story but from what I recall, the company in question has no ships yet because it's new, but can quickly obtain them and is run by shipping industry veterans.
Regardless, I don't really know why, because the heads of all the major ports in both the UK and France have said they expect minimal or no disruption. But maybe part of why they're saying that, is the preparations being done.
"Richard Christian, the port’s head of policy, said there would be “regular gridlock” in Kent in the event of a hard Brexit, and disruption to freight traffic on ferries and Eurotunnel services would have a profound impact on Britain’s economy. "
The UK survived by huge logistical effort and food rationing. It's now led by people I wouldn't trust with the logistics of a trip to Tesco.