I think that 'education' is more than just 'learning' and 'studying'. Actually, the term 'education" originates from Latin ('ex ducere", i.e., to conduct outside), so it means to provide guidance to someone (especially young people) so that they can 'go outside' and have their life in the society, establish good relationships with others, make a living with their work, and so on. Learning and studying are tools for education, however they aren't the only tools for that, and, especially, they aren't the ultimate purpose, which is 'education' in its broadest sense.
From this perspective, singing in a choir is extremely educational, as it develops social and teamwork skills that are crucial for young people in order to realize that, in a social environment, collaboration is much more important than a 'soloist' attitude. In a choir one has to diligently sing his/her part, one has to study music before rehearsals, follow the conductor, listen to the choir mates to find the right pitch and prevent that the individual voice is too prominent or too weak, and so on. All these aspects have a corresponding counterpart in social life, for example when preparing a meeting, when attending a meeting conducted by someone else, when listening to the opinion of others and explaining one's own opinion, and so on. This is, in my opinion, the greatest educational value of choir singing.
Many years ago (1987 or 1988, I guess: I was a young engineer graduated since few years) I was interviewed for a job selection. I clearly remember the reaction of the interviewer when I said that I used to sing in a choir: she was clearly enthusiastic, and wrote plenty of positive remarks about that on her notebook, probably much more than everything she wrote about my degree or my previous job... The final evaluation for the job selection was very good
Then, of course, singing in a choir may also imply pure 'learning' and 'studying': music notation, sight-singing, differences between music styles and eras, composers and their respective music periods, theory of harmony, etc., are all knowledge components that may be acquired or improved through choir singing. However, again, I think that 'learning' and 'studying' do not represent the core educational value of choir singing.
Max