Spoke with a knowledgeable baseball guy yesterday. He's coached at a few different colleges, both D1 and D2.
He said that many D2 programs focus on developing talent to have guys ready as upperclassmen. He said that many have J.V. teams and automatically put the freshman there to practice, play a j.v. schedule and develop. As they work, progress, and develop, they are put on the varsity roster or sometimes move back and forth depending on the situation. Kind of like having their own juco program in house.
As for D1, the idea is that you come in ready to contribute and play. If you're good enough, you play. If not, they don't wait around long before recruiting someone else or bringing in a juco.
What I've seen is that some D2's have j.v. teams and the schedule on the website. Others have a j.v. team but don't include it at all. I always thought it was a way to boost enrollment by bringing in players and if a few are good enough, they get to move up to varsity.
The guy I spoke with said that yes, D2's will bring in some J.V. players who won't play varsity as a means of boosting enrollment, but that by and large, the focus was on developing talent.