Still don’t quite understand what you’re asking about here. Files don’t delete themselves.
Sounds more like you assumed that because aliases existed in one folder they represented actual files rather than pointers. So you or someone else or another app(?) deleted the originals by mistake and the pointers remain but now point to non-existing files. But how is this FCPX’s fault?
Some 3rd party backup apps perform an archiving (ie compress/delete originals after backup) which can conflict with aliases. So this is a case of carefully reading the manual and disabling or exclusion rules so the backup app doesn’t burn you. Like this one has it sounds like unfortunately.
Noah
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