Kevin,
My point there,Keith, wasn't whether Jackie Walker knew that Holocaust Day is, officially at least, about all genocides.

My point was that she should not have asserted publicly that it is not, based only on her own prejudice which was proved false.

To make that false statement was a slander against Jews and her wilful ignorance does not excuse it.

It would be equally wrong to denigrate Nakba Day for not commemorating other comparable events without checking first.
(I have checked, and it does not.)