Skipping a full year of development in high school to enroll a full year early for ice hockey makes no sense to me, at all.
It depends on how you look at it. Consider men's hockey, where players routinely go play juniors after HS and delay their college entrance. Those going straight to college from HS have become a smaller percentage compared to decades passed. In theory, even the best recruits would maximize their readiness for a first year of NCAA competition by playing juniors first. However, the top players usually do go straight to college, because they don't plan on competing in the NCAA for all four years of eligibility. Each one has to make a decision based on what they think is right for them.
In women's, there are still players who aren't sold on playing hockey at the highest levels for as long as they can. Former Gophers Rachel Ramsey and Dani Cameranesi come to mind. Ramsey didn't show a lot of interest once she graduated, but got into other pursuits. Cameranesi won a gold medal and soon moved on to the next phase of her life.
There are also scholastic considerations. Several family members have combined the final year of HS with a first year of college courses. People want to challenge themselves in different ways. Everyone has their own plans for life, and I don't feel qualified to judge what I don't know.
People are always comparing Primerano to Harvey for some reason. IMO, it is hard to do, when one accelerated a year and the other was centralized, and thus, her college entry was delayed a year. There are advantages to being older in college, no question. Depending on goals, there can also be advantages to finishing a degree earlier.