Could it be evaporating machine oil?
Perhaps you bought an oil filter that is so fresh that the evaporating oil, that was used in the stamping process, hasn't evaporated yet. Or perhaps a batch of bases, that yours came from, didn't go through a wash process. Or, as you suggested, perhaps it is applied to prevent rust before the customer uses it I would hope that this is the one.
Whatever the source, I would think that Fram would have selected an oil that is compatible with your engine.
In a Tier 1 manufacturing facility that I used to work at before retiring, we often received parts that were still covered with evaporating oil. Our specifications for steel stamped components included an acceptable range for the suppliers to apply evaporating oil. That range was intended to provide enough evaporating oil that the stamped parts would arrive at our facility rust free, but also not have excessive oil.
The amount of oil, shown on the boss in the pictures you attached, would have been acceptable. Present, but not so heavy that it pools or drips.
Based upon my experience, working with suppliers of bare metal parts, I like seeing a light coat of oil on an oil filter. It is a given, if there is no protection on bare metal parts, they will rust. Based upon relative humidity where the part is stored, it is just a matter of time. Then of course, we would have all kinds of irate comments about the lousy quality of a filter manufacturer.
