I take free pass to imply you don't have to do anything. Preferential treatment is more like - this person is good enough to do the job and do it well, and they have a background we want to support so that's an extra positive.

I was once passed over for a job, and I somewhat knew the female candidate who got it. We were equally qualified, and I may have been slightly more experienced. I think it's likely that was preferential treatment (I could be wrong, maybe they just liked her more, maybe it was arbitrary). I think that's awesome. I most definitely wouldn't call it a free pass.