It is not uncommon for coaches at some programs to sit down with many players in their junior year and tell them if they get drafted, they are considered gone.
My son was told, at both schools offering him a scholarship, unless injured, he was there for 3 years. They expected him to get drafted and leave as a junior.
This is how recruiters plan in advance. I don't know much about the recruits listed, but I would imagine some of them won't set foot on campus. Some current players expected to get drafted, if it doesn't happen, most likely will be asked to move on.
Every once in a while a player that is drafted, one who has made a significant impact for the team, not happy with is draft position, will get the ok to stay. He most likely, with his experience, be more of an asset staying rather than leaving.
I am just relaying our son's experience and others that we know of who knew after 3 years they were gone.