Well, I seem to be adept at answering my own questions! For the benefit of someone else with the question: I did some research to learn that the oil cooler lines are actually coolant lines that flow into a "pancake" style heat exchanger at the oil filter. So that nipple on the right-angled...

I just went through replacement of my front lower control arms (along with tie rod ends and sway bar links) and had some moments of frustration until I uncovered the order, which made it much easier. My 2008 XC70 has 181K miles, and everything in the suspension is original. For the benefit of others...