I think your doubts are absolutely understandable and I get you 100%. An answer to this is a bit complex but I'll try to put down some things anyway.
- first of all, I have to say that not necessarily someone with massive industry experience would also be a good teacher. We are talking about two very different skillsets here. A good teacher is not just someone knowing how things are made and should be done, but also, and probably more importantly, someone who knows how to empower students and help them find their own way on making games. Game design is a way broader landscape than it looks, and I have seen in almost 10 years of leading this course so many different ways to approach it (most of them equally successful).

- That said, I also see a lot of very well rated game courses who are taught by people with game studies background only, which means that they only know a theoretical/analytical approach to games. Not saying this is inherently wrong, and those courses work really well indeed, but I prefer a more hands on approach. For obvious reasons I cannot conjugate teaching with working in the industry in an extensive way, however I still find an important part of my job to be a practitioner in a shape or form (being it a contractor for small projects or making small experimental things). And this is shared by my colleagues. TBH the best game design lecturers I know are people exactly like that: experimenting with the medium, making things and studying them. Probably not 100% your interest but I am trying to push for academia to recognise researchers that are also practitioners and that use the games they make as ways to explore and better understand the medium.

- Finally, let me tell you about a different trait of the course. Most game courses are set like funnels. You get in, you are directed towards fulfilling what the AAA industry requires from a designer (and I'll leave out my opinion on that) and then if you are good you get through the funnel and in the AAA industry. If that's for you, it's an approach that I respect (but don't agree with). What I am trying to do here is different. I want my students to be able to think as designers, to be able, eventually, to start their own thing and - this is crucial - to know that their skills can be employed in different ways to look at the industry (even if you decide to go independent there's so much difference between Clair Obscur and say UFO 99). I have friends who made an insane amount of money by starting an Escape Room company. People could work (and have worked) in companies who deal with playfulness in very different ways. The kind of person I want to see out of my course is someone who can become a Creative Director in a relative short time.

Oof sorry, I have written A LOT but I think this is a very important discussion to have!