So my server runs on Linux and has been running on Linux for about year, and I currently have this specific setting enabled. I haven't specifically "crash tested" the setting on Linux (say by force unmounting my media network share and manually running import), but I haven't experienced any spontaneous deletions of library items either. Generally speaking all my media is on NAS drives mounted through CIFS, and my NAS drives are usually available, but my NAS has gone down temporarily in that time and I haven't seen MC removing my entire library.
I'm not a dev, so I don't know exactly how MC tests, but one thing to know about my config: I did not add the root of my drive mount to my auto-import list, I only added sub directories within the drive mount. For example, I did not add /mnt/media to the auto-import list, instead I added /mnt/media/Audio and /mnt/media/Video, etc.
This may be important because if MC tries to stat either of those subdirectories with the network drive unmounted, it will get a "no such file or directory" which, when you're talking about the root directory for scanning, probably signifies a missing drive. If you instead setup auto-import to watch the root (/mnt/media in my case), that directory will be there whether the drive is mounted or not. So the stat would show a directory there, which, when the drive is umounted, would be empty. In that case it's possible that a missing drive could lead to mass "fixing" of broken links!
Again I don't know how the detection actually works on Linux, I only know I use the setting and haven't had any issues with the configuration described above.