I've never understood the infatuation with with acceptance rates for MFA programs. They mean absolutely nothing. They are rounding errors at best, statistically insignificant. There is nothing that can be gleaned from such small sample sizes. I see people make comparisons about how it's harder to get into most top tier MFA programs compared to top tier law or medical schools. It's apples and oranges and shows limited understanding of the application processes. With virtually all professional graduate programs, and those in the social sciences, there are standards and a pre-sorting process that occurs to apply. In the US, most applicants take the GRE, LSAT, GMAT, or MCAT and coupled with their GPA have a baseline understanding as to whether they should apply to certain programs. So the high majority of applicants to top tier programs have sorted themselves and already meet traditional requirements -- they all look fairly similar on paper. Further, graduate programs have a post-assessment process that influences which candidates they admit. They want to to have the confidence that their graduates can perform well on board exams, bar exams, internships, etc. These numbers matter to them and they select students that demonstrate an ability to succeed in these areas. That is not the case with the majority of MFA programs. Most don't require GREs, and there's no post graduate exam or certification to say you're a writer or artist. It's all nebulous. Applicants come from all skill levels and the sorting is done during the application process. There are few standards. A "strong writing sample" is difficult to quantify. This is all art and personal preference. Yes, there's a degree of basic craft and technical understanding one can have, but it's not required. Depending on the ADCOMS they may value raw talent and a distinctive voice rather than a highly polished voice echoing familiar canons.
And most importantly, it's not just about your application. For many of the top tier programs, they're building cohorts that can benefit and push each other. So they will often not include writers with similar styles, even if they are the best applicants that year. They want of diversity of thought and not echo chambers. So keep that in mind more than spurious statistics about admissions. Of the thousand applications a program might receive, maybe fifty are interesting and competitive. Of those, it's searching for the right combination to create synergy for the cohort as a whole. This process is not intended to be science. It's magic.