Transition from highschool to college is HARD for many. I don't know how these D1 athletes jump right in like he has. They have so much going on and are under a microscope.
Props to him for taking care of himself 1st and being open and honest with his team.
This is a good point that I don't think gets talked about often enough. College isn't easy for everyone - between living away from home for the first time and taking more difficult classes, many struggle to adjust. I think the transition for basketball players has to be about the most difficult of any sport.
For example, true freshmen regularly shoulder a lot of responsibility on their teams (whereas most football players redshirt or have limited roles). Additionally, the season spans both the fall and spring semesters, whereas many other sports only have an active season during one semester. Finally, the amount of travel basketball players have during the school week can make it difficult to stay on track academically. Iowa basketball played on the east coast last night, and likely were on their way home in the early hours of the morning today.
Some of these kids are only 17, 18, or 19 years old and they instantly become highly visible people on campus, shoulder a lot of responsibility for their team, and then also need to deal with academic challenges (not just maintaining grades, but deciding what classes they want to take). There's a lot of people that get overburdened simply trying to decide what to major in - which is a big decision as it will have a big impact on the rest of your life.
All this said, it's understandable that DJ may need to take a breather to feel like he can "catch up" with his life. And frankly, it's kind of surprising that isn't more common. I imagine the same struggle is there for many players, but most probably feel too uncomfortable to acknowledge and address it.