Did you read the story, or even the headline.
DeVos "cancelled" her trip, she wasn't banned.
She is booed everywhere she speaks in the U.S. Why would it be different here? 
DeVos's push for "school choice" is  essentially a  push to segregate schools again, backed by a minority of Trumpites.
That is why the majority in the U.S. greets her speeches with boos.