I have asked before, do you know if the battery itself has been redesigned?
The Battery yes, the cells inside no. The parameters for charging (max current, max voltage...) and disconnecting it (due to low voltage, avoiding deep-discharge) have been modified, as far as I know the temperature limits as well, quality control has been approved, cells are now separated by fireproof spacers etc.
It obviousy did help but nobody knows which measures did the trick...
So, we are awaiting "proof" that it is a major threat? Hmmm...... I think this system failed to meet the required conditions.
Yes it did, but it is "allowed" to do so with a certain (low!) probability, as long as you do not risc a catastrophic loss of the aircraft. Is is not clear (and probably never will) what would have happened, if they would have continued flying (e.g. because they were in the middle of the atlantic). Maybe the fire would not have spread, only the battery may have burned out. A major event, but not a catastrophic one.