What determines the "academic minimum requirement" for schools?

Answered

No college or university will not provide on their website a chancing engine because they do not wish to share their admissions methodology publicly. If this were the case, everyone would game it.

CollegeVine has a decade or more of data from tens of thousands of admits so when you get a % percentage probability to admit rate, it's more nuanced than the college's official admit rate. This is because CV takes into account your course rigor, the quality of your ECs and amount, the quality of your additional test scores like APs, and your demographic information like race, gender, orientation.

So when you look up an admit rate for say Barnard, it's going to be 11.8% (1097/9314 for Class of 24'). On CV depending on your input data, that's going to be a long reach, reach, hard target, target, or safety and you can play with your input data and improve your weaknesses if you are a 10th or 11th grader. If you are a 12th-grade senior, well there is not much you can do to change your chances right now except to pick schools that you have better odds of getting into.

If you want to get the best idea of academic requirements, the only way you are going to do that is to research each school's reported Common Data Set. This is standardized data set each school publishes for purposes of transparency and reporting to ranking agencies like US News World Report etc. What you will find on a Common Data set are actual admit rates, class ranks, test scores, GPA, and a rubric of how they evaluate candidates based on Character, Grade, ECs, Geography, Legacy, and another dozen criterion. I'm providing links to 2 girls' schools so you can compare and contrast how one school does things versus another school.

https://barnard.edu/sites/default/files/inline-files/CDS_2019-2020_completed.pdf

https://www.mtholyoke.edu/iresearch/data_set

As I mentioned in my previous response you need to expand your search and do more research on other schools that are a better fit for your academic, extracurricular, and personal preferences. I would start by looking at various common data sets of schools that you are thinking about and then figure out how wells you fit with them and what your chances are for getting into them. And if financial aid is a concern, I would run a bunch of schools through the NPC Net Pricing Calculator on the individual college's websites or through College boards Big Future section of their website under "tools and calculators".

To clarify what "clearing the academic threshold" means is that you meet the minimum standard for what CV feels that school requires. But if CV states your GPA and coursework both need improvement that means that most "admits" have a better UWGPA and have better course rigor than you. This means on average they take more Honors and APs and have successfully received better test scores on them. These terms are not mutually exclusive but connected. As a rule of thumb if you meet the requirements and are on track with your GPA and course rigor that means you will fare better in getting admitted. To be fair to yourself and your chances by picking a few reaches, more targets, and some safeties.

Good luck with your college admissions process.