1) First of all, it seems that the leading question of the discussion "Is it acceptable to publish student names with the label stupid question?" is not correctly formulated. A part of the the question contains a statement which is actually faulty: the names of the students are not revealed, only the first names are mentioned, which are all very common ones. The format like Donald T. or Emmanuel M. does not permit to identify the person, so that the anonymity is fully kept (hence, GDPR has nothing to do with this). Moreover, such a format of names is usual in classic literature. Actually, to name the person only with her/his first name means precisely that you do not want to reveal the identity of the person.
2) I don't think that the objective was to ridicule the students, but rather to make them attend more or/and to make them understand that they are simply too lazy (since they do not recall even basic notions). In engineering schools, as was remarked earlier by @A Simple Algorithm, students should have at least basic notions of the trigonometry (the trigonometry is usually covered in high school before the university), because it is used throughout all the university curriculum. Same remark concerns decibels: this is a very basic notion, which is covered during the 1st year of studies. So (@J.R.) nobody mocks. After all, it ain’t funny to have students with such a poor level.
3) In France, the higher education is free, so that it is easily accessible even for the lazy students. Don't you think about those students from other countries, who have a talent and would like to study, but can't do this because their parents can't pay??
4) Also, I don’t understand why it is acceptable to widely rank teachers and professors on the Web sites, and why it is not acceptable to do the same with the students (thought on this Web site the rank of the students is not published)? And on the Web sites, the professors are fully named, not as Antoine W. or Sven F. So strangely, nobody thinks about GDPR or FERPA for the professors and teachers.
UPD: the initial question was modified so that now it is clear that the actual names are not revealed on the website in question.