The article is clearly about religious brothers.  Not religious women and not priests.

But I do very much agree with you that a major factor (but by no means the only)  in the decrease of vowed religious men and women and priests as well is due to our withdrawal from high school education.  Most vocations took form during those years for the orders who ran each school and some for the diocese as well.  But starting a 17 or 18 year old in actual formation was a serious mistake, as we came to learn.  However, every religious will testify that it was in high school that they discovered what real adult religious life was by watching and talking to and visiting with one or two of them that they particularly admired.  Then, a gradual and gentle program of discernment through college or early work life can take place before actual formation is started.  But being in schools does very much matter.  If only there were enough of us to return to classrooms.  Times are so very different now.