I had a trip a year and a half ago or so with a connection each way. On every leg, I was assigned to a middle seat except one, where I was given an aisle. I got really excited about that one flight until the DL gate agent said they were reassigning seats. The new seats came up after they scanned the boarding passes and printed out on receipt paper.
I got switched to a middle seat again.
Thankfully, the lady next to me was friendly enough to swap with me.