I take it from your post that you did not pay any seat selection fee nor make any preferred selection, and the three seats you highlighted are just what the system coughed up? For no additional cost, just because you were an adult traveling with two children?

What it would appear to show is not some intentional pettiness, but rather their seat assignment algorithm is very flawed. It booked two more-desirable aisle seats towards the front of the plane, when Basic Economy should have caused it to seat you much farther back (where I assume you ended up, in three seats more logically side by side). What originally happened makes no sense unless it was a weight-and-balance thing. A parent of teenagers would have loved it.