The question is going to be how much of that unknown/untested percentage actually matters. I mean, there's even a question of how much the 12.25% of known test regressions actually matter.
> Also, I have major issues with dumping GPL userspace utilities, for an MIT license suite, that is known to not be feature complete, only, and literally only because it was written in Rust. This does not make sense, and this is not good for users.
Thinking about it, I guess I have to agree. This allows ubuntu to avoid releasing security fixing patches if they so choose. You can't do that with GPLed code. It means they can send out binary security fixes and delay the source code release for as long as they like or indefinitely. Which is pretty convenient for a company that sells extended security support packages.