The main potential problem these days (in my view) is whether a print finishes without crashing or delaminating from the print plate, which also has workarounds... but that's only potential printer damage, not a fire.
https://www.reddit.com/r/anycubic/comments/1j4kfsr/guys_just...
I have never had an issue with fire with one of my machines, but I have had 3 or 4 of them fail because they detected inconsistencies with their thermistor, immediately removing voltage from heating elements until they can be convinced that the problem has been resolved.
IIRC Some enders shipped with a faulty marlin firmware that had faulty thermal shut off code, and you used to receive a pamphlet with the printer to update the firmware immediately. I suspect that a lot of people simply did not.
Dont know what this bloke did, but between anycubic and the kind of person who carries a flaming 3d printer in his arms, something went very wrong.
But, it's not really straight propaganda that the well designed machines (Bambu, Prusa, and many other vendors) don't have these issues.
You can find equally alarming statements about all sorts of other poor quality goods.