I think the answer to both of your questions is yes - a tragedy is less likely. But one is still possible regardless and the concern I have had has always been an expectation or implication that the RO must not allow one to happen by adhering to rules some of which might not be able to be complied with in some races.
I think the later versions reflect this better - obviously not everyone shares this view and this is clearly an important debate so I feel everyone with an interest should be contributing, its just a shame its got so personal. Not being a RO myself I am still concerned if the organisers of some classic races are still worried themselves. Anyone who doesn't think it matters have a look at Amblesides website re this years Langdale - I'm optimistic it will be OK but if it isn't what a disaster for fell running.