They're not switching to Rust, theyre switching to pushover licenses. It wouldn't surprise me if in a decade or two they'll try to make a kernel or swap to a pushover licensed one (e.g. FreeBSD) and make Ubuntu proprietary.
Only for corporate (Where presumably someone will tell you which is necessary). If you still think that's a problem you can have server go to Ubuntu and Desktop go to OpenSUSE
The wealthy are absolutely conservative, where did you get the idea they were progressive????