Since people have been talking about Dreamers going for Cnada, it says in Section 11 of the regulations under the Immigration and Refugee Protection Act of Canada. That section requires an applicant who is applying to immigrate to Canada permanently to apply from the applicant's home country unless the applicant entered his or her country of residence legally.
Legally being the keyword here. DACA are not legal immigrants so allowing them into Canada through any stream would require a change in law. Also, they still have to take English test, no matter where they studied. In short, it's a long process for them which hasn't yet started.