What does it mean when a course says there are no deferred midterm??

From my experience it usually means that the %-weighting from the midterm gets put onto something else if you MSAF that midterm (usually gets placed into the final exam's weighting). This is as opposed to deferred midterms which mean that you'll still have to write the midterm you MSAF-ed, just at a later date.

Have a read through your course syllabus/outline. It will say there what the deal is with MSAF'd midterms or assignments.

Though "no deferred midterms" sounds like you'll have an alternate write date, or a makeup assignment.