Re: Though you're able to share content from Khan Academy to Google Classroom, please bear in mind that the assignments are only created on Google Classroom. These activities are not assigned to your class on Khan Academy. For this reason, Khan Academy cannot provide feedback or share a score on your Teacher Dashboard when completing the assignments.
For me, as an end-user (teacher), not knowing the challenges to do this, it would intuitively make sense that by creating the assignment in Classroom, it could (and should) then be assigned to my class in Khan Academy. As is stated, it is NOT assigned. This is confusing to me, and can be confusing to students.