That's a heck of a stretch. Talk about dodgy journalism. Still, I suppose it is GB News. DFDS banned on-board charging of EVs 15 years ago after a single incident on one of its ferries. I cannot find any reference to any ferry operators banning or planning to ban EVs from being carried in the future.
Here's a video showing an EV fire being suppressed and controlled in a couple of minutes:
Tim H. 1986 4/4 VVTi Sport, 2002 LR Defender, 2022 Mini Cooper SE