Long time lurker first time post.

2 weeks ago I purchased 4 tickets from DTW to MCO for a trip in a few weeks and wanted to keep the party all together.
Upon booking the flight I noticed that the "preferred" seating areas behind EC+ middle seats were blacked out on both sides and all 3 rows in preferred.
The only available seating that were all relatively close together were all the way in the back or exit row but since I have two young kids with me I didn't choose exit row.

Has anyone seen that happen before where the middle seats were not available to choose? I've been checking to see if the seats open up so we can sit next to each other but still nothing.