I've noticed many fasteners come with a dab of grease.
Are you sure it was grease and not pre-applied Loctite (thread lock compound)? I have also seen screws/bolts come with "something" on them but in every case it was a threadlock compound. The small bolts for my brake disk plates come to mind. If it's threadlock compound then basically the manufacturer "probably" wants that fastener to go on dry.