I understand your take, however, as I understand, they have a ton of high school applicants every year. Personally I never attended the camp, as I attended the academy, but I worked at the camp for a number of summers as a part of a flagship ensemble that toured, so I am still familiar with it. Did your daughter specifically apply for the high school program? Because otherwise, they do try to keep people together in accordance with age group, this has a lot to do with the social context of the camp. I apologize for your daughters issues with the rules of supervision and such, however it is for the middle school aged students' safety. I also know that these rules are less strict for the high school campers. But there is still a rigid structure (even at the academy). And to be honest, though the students (including myself at times) may have issues with this, the camp has certain liability for 1500 students, and 500 academy students at a given time. With this in mind, a little bit of slack should be given, in my opinion.
It is extremely difficult to cater to the one individual student who is more talented than the rest of the intermediates (when there are many talented high schoolers already there) and just throw them into the high school camp after the the student is already on campus. I know it sounds cold, but there would be a whole slew of issues that would come out of revamping and reassessing this sort of situation. It has nothing to do with your daughters talent, but merely what camp she ended up attending (intermediate level). One cannot jump from the intermediate to high school level once already on the campus...unfortunately, this is an issue that probably could have only been solved by calling before attending or accepting the offer. I am sorry for this poor experience, it must have been troubling for both you and your daughter.
As well as that, just because one student may be more mature and in need of less stifling boundaries, a majority of the students do need this kind of supervision. They have to keep the students safe. Once again, I am not trying to attack you, I am just playing devils advocate and adding another perspective to your issue. Nonetheless, I am sorry that you had the experience you had. I hope your daughter would consider the high school program, as it is indeed invigorating, and an amazing experience.
Also, trust me, though there are many students on campus at a time, the instructors at interlochen DO take great care in who they place at what level, however, like I said, they do have their age restrictions based on camp. Once again, sorry for the bad experience. But there is a vast difference between the intermediate level and the high school level, however they both have their benefits.
However, OP is about the high school jazz camp, which is again an amazing new program, with a great faculty. While I respect and love the jazz program as it used to be, I am fully behind the new format that they have had since last summer. It seems to be extremely stimulating, and one should be able to get a lot out of it.