I don't know whether you should be pruning the bushes to open them up, but my guess would be 'no, not necessary'?

I was lucky one year to find near where we had lived was a 'wild' blueberry patch and we spent some great hours harvesting them. They grew well in the local peat soil, and were very healthy. No pests except the birds. They were tall bushes, too.

Everyone became quite sick of blueberries that year ... lol. I have been collecting a few plants the last few years so hope to have some nice harvests in the years to come. :) I bet you will, too!