Is this really surprising?

Let's just look at US demographics right now: https://en.wikipedia.org/wiki/Demographics_of_the_United_Sta...

Looking at the chart, I'd expect to have seen a drop in enrollments among those younger than early to mid 20's over the last few years. 6% easily seems en par with the demographics shift.

If that reasoning is correct, we'll see a slight recovery or stabilization peaking in about 5 years or so and then steady declines until who knows when.

Colleges all over the nation will be competing for students for the at least the next 2 decades.

Prices will drop, and offerings will probably be more tailored to offer better value, and that may improve/stabilize enrollment rates somewhat, but the overall trend will be down.