I have worked at many bootcamp-style educational programs.

Teaching in a bootcamp-style environment is a team endeavor. Recent graduates can be a part of that mix.

Generally, it makes sense to hire some of the instructor pool out of recent graduates. It is often difficult to find instructors at all. The recent graduates know the curriculum. It also helps those recent graduates develop a deeper understanding of the material and extend their job searching window. It can be a form of peer learning that some students respond well to.

There are also definite limitations. Primarily, the recent graduates might not have great teaching skills, knowledge outside of the curriculum, and knowledge of real-world applications.

I get the impression that the business model for these bootcamps is largely the modeled after the one used in startup funding, where the bulk of the money will be made on the top 5-10% of the class.

There's also likely some element of grabbing mind-share while they work to automate the process (plus, gathering data on who make profitable students). Eliminating the instructor will allow N to grow much higher than 150 per course and reduce costs dramatically.

I wonder why? I learned most of what I learned in university from student group, and sophomores teach freshmen there. I learned as a freshman and taught as a sophomore. It is normal.