According to https://www.washingtonpost.com/news/grade-point/wp/2016/06/10/40-percent-of-u-s-colleges-enroll-fewer-than-1000-students/ , “about 40 percent of American colleges enroll 1,000 or fewer students”. The article also says that these colleges have lost about 5% of their enrollment since 2010 (through 2016 when the article was written), while colleges over 10,000 students have grown slightly.
So it is certainly possible that a large number of small colleges are in danger of closing, even though such closings may not reduce the capacity by that much (closing 40% of the colleges which are the ones under 1,000 students will reduce capacity by much less than 40%).