Moving from one Learning Management System (LMS) (MyCourses) to another LMS (Canvas) always has certain limitations. As such only certain types of content come over from Moodle into Canvas. No student data, submissions, grades, forum postings (instructor postings included) migrate over. The Migration Map below provides a map of what items did and did not migrate from MyCourses to Canvas.
First, here are the assignments and activities which migrate over:
Second, here are the assignments and activities which do not migrate over (mainly due to student data not being exported):