I think a lot of things use pre-shrunk fabric these days. I've got t-shirts that haven't shrunk, and t-shirts that have. Unfortunately a lot of band shirts bought at concerts fall into the latter :(.
Even cheap band t-shirts don't shrink in our dryer. I have sweaters that I am confident would have shrunk in the past, but do just fine here.
On that last, I almost forgot I had direct evidence. We visited a place that shrank some of our clothes that we had washed many times back home.
I tend to find that older (10+ years) t-shirts shrink a lot. Even if I don't wash them.