Although mathematically finding a MAP estimate involves finding the argmax of a probability mass function (or density function), and that's exactly what we're doing here, I think that terminology is specific to the Bayesian framework.

https://github.com/davidrosenberg/mlcourse/blob/gh-pages/ConceptChecks/1-Lec-Check_sol.pdfhttps://github.com/davidrosenberg/mlcourse/blob/gh-pages/ConceptChecks/1-Lec-Check_sol.pdf