I'm sorry to belabor this but I'm genuinely not understanding what you're saying in this reply. I haven't operated large scale systems. I'm just an IT generalist and casual coder. I acknowledge I'm too inexperienced to even know what I don't know re: running large systems.
I read the parent poster as broadly suggesting configuration updates should have fitness tests applied and be deployed to minimize the blast radius when an update causes a malfunction. That makes intuitive sense to me. It seems like software should be subject to health checks after configuration updates, even if it's just to stop a deployment before it's widely distributed (let alone rolling-back to last-working configurations, etc).
Am I being thick-headed in thinking defensive strategies like those are a good idea? I'm reading your reply as arguing against those types of strategies. I'm also not understanding what you're suggesting as an alternative.
Again, I'm sorry to belabor this. I've replied once, deleted it, tried writing this a couple more times and given up, and now I'm finally pulling the trigger. It's really eating at me. I feel as though I must be deep down the Dunning-Kruger rabbit hole and really thinking "outside my lane".