Yeah, the file system connector probably needs to be firing more events, especially the property-related events, so that the same kinds of events are fired whether an 'nt:file' node (with 'jcr:content' child) is added internally or externally. Do you want to log an issue?
I have no experience in logging issues on JBoss projects, but I can probably learn how to do it, but if you would do it "for me" that works for me as well
Logged as MODE-2189.
Thanks for this and the provided support