Small bit of oil in coolant, a bad sign of what the future holds?

Just replaced my leaking water pump and coolant filter. Coolant looked perfectly fine and clear (well, red), as did the reservoir. But when I pulled the filter, it had what looked like liquid peanut butter all around the top.

Read plenty of topics to know oil in the coolant is a sign of a bad head gasket, but what about such a small amount and in the filter that hasn't been replaced since before I bought the truck, so who knows how many years old?

 

Sorry for vanishing after posting.

I was considering replacing the filter again anyway after a few weeks since I didn't replace the coolant pump properly. Didn't have a way to properly drain and store all the coolant so just put a large container under the front of the truck and pulled off the pump, letting the coolant pour out into the container. Then dumped it back into the truck when done (only lost a few gallons), but of course it pouring through the engine down to the container made it collect dirt that the new filter will have to remove.