I've never had any type of high tier status at any chain. I've never worked in a property that has a separate elite check-in line.
I would do as some and stand in the line and then ask the clerk if someone was manning that line.
I'm sure most properties that have the lines are elite heavy. Do some people think the lines should be manned at all times? What happens on the day there are 50 non-elites checking in vs. 3 elites. Should the line be staffed at all?