NHTSA Complaint #11491401 — 2021 GMC YUKON

I own a 2021 GMC Yukon Denali that had TOTAL BRAKE FALIURE last Tuesday. I had it towed to a local GMC dealer and are repairing it under warranty. I was lucky to be on a back road when my brakes went out. I had no warning lights come on prior to hitting the brake pedal and was able to coast to a stop on the shoulder When I applied the brakes, the pedal went to the floor and did nothing. You can't stop the car with the parking brake because it is electric. My concern is what if I was on a busy road when this happened or what if this happens to a family in traffic they could be seriously hurt or worse yet killed. I do have good photos of my instrument panel with all of the warning lights coming on after I tried to stop. In good conscience feel that I have to at least try and report this to GM, the state and anyone else that will listen. If nothing comes of this at least I tried and just hope no one gets hurt if this happens again. My wife refuses to ride in that vehicle until I have solid answers. The dealer said they will have my car repaired this week and are replacing the master cylinder and ECS This is fine but why did it happen and how can I be sure it won't happen again? I believe in GM and have a 2023 Yukon Denali on order. I would hope that after 3 years of this model they have most of the little quirks worked out. A rep from GM did contact me and at first was talking about buying my car back but changed that today. My case number is 9-8497380349 . The problem is I have no idea when my new car is coming in our should I just cancel it and find something else. In my opinion this is a very serious problem.