They do indeed burn differently, whilst EV fires can be difficult to put out they don't produce a 'river of fire' as can happen when a fuel tank is breached, they also don't (as in Luton) create a FAE. I have seen no evidence that 'officials' changed any 'initial reports', I do know that some news outlets deleted the lies posted by readers.
I'm not aware of any change to 'official reports' of the Melbourne truck fire, Janus the company who produce them have done a report which concluded that a cell overheated and caused a thermal runaway, what have you heard? If it's from 'Auto Expert' then don't bother directing me there, as he has a history of twisting the facts to fit his agenda.