A quick read of the article and this like pops up from the presenter:
'Allow your passengers the choice to know whether it is safe to fly with you.'
So she expects to turn up to the flight, announce there's an allergy, and then pretty much make them (the choice element is swiftly diminished) leave the flight or not have their snacks on the flight?
It did seem safe right up until the point she started asking every other passenger not to have nuts.
Sounds like she could have done more to speak to them prior to the flight and warn them of the allergy?