Why is that the bare minimum?

I also think that doc page is a little old. The feature is over 2 years old now and hot reloading is inherently "unsafe" in any compiled language. It's just letting you know that Rust's safety guarantees might go out the window if there are bugs in the code that handles hot-reloading.

Because that is what existing game studios expect, as shown by their customer list.

Also that was only one example, there are other similar ones.

Funnily enough, Mojang is on that list, and I remember recently watching a video[1] of Notch hot-reloading code while developing Minecraft, except it was with Java and I'm sure he didn't pay a dime for the ability to do that.

[1] - https://youtu.be/BES9EKK4Aw4

That live reload probably already works with Rust — they say they don't parse any source code, and instead analyze the compiled binary and debug info.