Yes, according to an article posted elsewhere, the Vatican does indeed "endorse" JCS, which was news to me. As I recall from the liturgical "excesses" of the seventies, it was not unusual to hear songs from this blasphemous, yet insipid, musical, sung (to guitar accompaniment, of course) during what passed for Mass in those days.
If I wanted a child to get a Catholic education, the last place I would send him or her would be a Catholic school.