I feel like this question has come up before but here’s my experience.
In juco almost half the kids on the fall team get cut when they bring the roster down to 30 something for the season. The story from the parents runs the gamut, but I’ve never heard “My son was cut”. Of the kids that made the cut, most all made it the full two years unless something very serious happened, like criminal charges or a death of a parent. Grades were never an issue, if your grades started to slip, you spent your evenings studying with the others in your position with an assistant coach and nobody wanted that…
Arkansas was a little different, although they closely monitor grades and class attendance too. (Sidetrack: coming from 2 years of juco to a program like Arkansas, my son was incredibly thankful for all aspects of the differences – food quality, facilities and technology – many that start in P5 D1’s are oblivious to the advantages). At Arkansas, if you don’t perform or progress, you don’t stay on the team. If you or your parents butt heads with the coaching staff you won’t play and you’ll eventually leave (saw this a couple times, including a freshman that was a juco first rounder the following year).
This was 2015 – 2017 and I’m sure the portal has changed the dynamics, but this is what I experienced.