That is not the point. It is whether or not the mapping is actually a path to the specific disk, or it is a path to a user share.
It is very common to have the appdata user share as cache-only, so it is all on a single disk. But if you have it like that, you could either refer to it as /mnt/cache/appdata, or you could refer to it as /mnt/user/appdata.
Either way it is on a single disk, but some people experience problems when using /mnt/user/appdata. The hypothesis is that somehow the user shares break the database.