Yes certain countries are on an expedited list but the government is also prioritizing processing cases where people have crossed the border from a few countries. Many don't qualify for asylum so they want people to be rejected as soon as possible so they haven't established themselves in Canada. The government has also seen that a good percentage of Canadians are concerned about the volume of people who're crossing the border on foot. They want to publicize deportations in the election year. Believe the target is 10000 this year. They also need to deport people so communities start spreading the word that asylum in Canada is not a guarantee. Unfortunately some of their community members have given them a false sense of security and assured them that Canada would let anyone crossing the border to stay in Canada.Actually they have categorized the cases and putting less complex cases on fast track as per their website.
Cases on fast track doesn't mean denial only.