I've ran Linux (various) for near on 20 years and ran it on hundreds servers for 15. I've only ever hit one such crash for an external piece of custom hardware with a noddy kernel module. Plenty of crashing kernel modules yea.
There was a bug with Intel GPUs that was unfixed for at least three kernel versions where plugging in an external monitor over an HDMI-to-Displayport adapter would reliably freeze the system the moment the kernel tried to modeset. That's finally been fixed from what I can tell, I believe it had something to do with a change to an NFS driver somehow.
Server hardware often doesn't need complex or bleeding edge kernel modules. You don't need sound or video, you don't need framebuffer resolutions, you don't even need that much in terms of keyboard compatibility. It's a lot easier to run a kernel of the most complex hardware out there isn't hooked up to your system. That doesn't mean Linux is bug free, it merely means that the kernel code for the limited hardware of your choice has been maintained well.
The real challenge for Linux or any kernel really is to run reliably on a laptop with an uncommon variation of common hardware, preferably sold for only a few months. That's where the real bugs come in.
I've worked on C and Rust codebases, though nothing near as complex as the Linux kernel, and I'm excited for this change as it will reduce the burden on the kernel developers to reach the same quality output, so we either get drivers faster, or drivers for hardware we wouldn't have otherwise received, or both.
As far as the fear of Rust kernel drivers that don't compile with GCC's Rust frontend, I trust Linus to keep the bar high on letting this feature in, and that kernel drivers accepted into the tree compile with just GCC as they always have.
Third-party drivers may not, but that's also true today if someone wrote a driver that only compiled with LLVM. This doesn't really happen in practice as it goes against the path-of-least-resistance for the developer: they'd have to switch their toolset out when working on that driver vs everything else, and the auto-building by DKMS would probably fail on them if they used it during development -- all of the conventions used by the rest of the kernel infrastructure will keep them in line.
(Frankly, I doubt that those would be resolved with Rust, or even if the developers all got attendants that would massage their feet.
The GPU driver developers are hugely busy with cranking support for new cards, and bugs in the older cards support are rarely tended to, when they are it makes headlines. I blame skewed incentives.)
There are also definitely kernel security problems (e.g. this from a quick google: https://www.cvedetails.com/vulnerability-list/vendor_id-33/p...). If Rust can eliminate a percentage of those then great.