In classic quizzes, the multiple answer question type allows instructors to preload student feedback for every answer choice, just like with ordinary multiple choice questions. That feature has been eliminated in New Quizzes in favor of summative student feedback for a correct answer, for an incorrect answer, and in general. I would like to propose that New Quizzes bring back student feedback per answer choice for multiple answer questions.
There are a few of advantages to this:
Currently, if you've selected partial match with penalty grading, it's unclear what feedback students will get on multiple answer questions. This would make the question type behavior easier for instructors to intuit.
Specific feedback on each answer choice advances student learning by helping students gain a granular understanding of what they got right and wrong, and potentially where to find remedial resources.
Many instructors (including in my program) have deep question banks that have already been developed to include student feedback for each answer choice.
Having student feedback for every answer choice would, presumably, make it easier to preserve preloaded student feedback when importing questions from classic quizzes.
Existing Canvas activities like, for example, continuing education courses, may have a requirement that students receive feedback for each answer choice.
For my program -- and I am sure I'm not alone -- the current functionality is likely to delay our implementation of new quizzes while we figure out what to do next. It would be much easier for us, and better for our students, if student feedback for multiple answer questions worked according to the expectations Canvas has established over many years now.