As far as I know WN's policy is First Come First Served now if there were later boarding passengers in the same party and they were saving their seat then that is a major no-no as you paid BS Seats. If this passenger wanted their party seated together they why didn't they pay for BS?

I would have spoken with the FA who should have said that you are more than welcome to sit in the exit row as you met the requirements and are there before the boarding family. I would have asked to speak to a customer service rep after the flight to see how WN can improve on the training of the FA's.

The person saving seats would do better on Delta where you pay to sit in the premium seats and you can get seats together. I would have told the person saving the seats that I'm entitled to these seats because I am here before your family or friends. Yea so you want to sit together then you should have taken care of this before hand.