Of course. Unfortunately, schools tend to see RH as the only "real" business Linux option. That's partially because for many businesses, it was for a long time. There is a fairly large corporate RH user base, as well. Lastly, there is a certification with RH's name on it, and for schools, this is probably the clincher, as schools are big fans of certs. (For no other reason, this can allow them to judge the effectiveness of their teaching methods. The more students that pass the cert, the "better" the class, meaning that the teacher can use it to argue for more responsibility (er, money) pointinf to the results as proof of their skill.
Lastly, they have to teach you on something, and no matter what they pick, somebody's going to complain. In this respect, they can use the above reasons and others as excuses. And, lest I forget, RH has some pretty impressive discounts to schools, which is probably as important as any other reason.