Whatever your view of student-debt cancellation, the inflation argument is a red herring and should not influence policy. Taking that logic to the extreme, canceling food stamps would do far more to reduce inflation—but that would be cruel and inhumane, and fortunately, no one has suggested doing so. A closer look at the student-debt-cancellation program suggests that the new student-loan policy may even reduce inflation; at most, its inflationary impact will be minuscule, and the long-term benefits to the economy are likely to be significant.
Honest question: what do you think is his reasoning to not promote cancelling all student debt? Or even, why not provide everyone with food stamps?