If indeed Death Eaters today had attacked the school for Muggle-borns, but had all been killed, the Muggle-borns at MMA would not be inclined to meekly submit to a wizard who talked as offensively as any Death Eater, just because this wizard was wearing a badge. Dawlish, and whatever Aurors he had ordered to come with him, might all be slaughtered today, unless Amelia acted now.