Well then I wouldn't need to call in and ask for those. Just to be clear, the situation here is that all aisle and window seats are already taken by the time I book. I have been told that unblocking those seats is an unpublished benefit, and I am going to take advantage of that.

The frequency of gate agent swaps has gone down a bit (but it still happens occasionally). I've been suffering now from a separate issue - phantom equipment swaps. I've had my seat changed on 3 of my last 4 flights before it even goes to gate control even though the plane configuration did not change (A321->A321 and Delta only flies one A321 config). While two of the times it has been minor (e.g., getting moved from 38C to 37C), my flight this afternoon was moved from 26C to 27A. While 27A is not a bad seat (it is missing seat in front of it), I would still prefer my original aisle seat.

I spent several hours on the phone yesterday trying to get this resolved (starting 20 minutes after the non-equipment swap equipment swap) but was told consistently that Delta tries their best to maintain seat reservations and, therefore, moving someone out of the seat I originally had (even though they had just been put there 20 minutes ago) was just not allowed.

So apparently it is okay to completely reseat all passengers for no reason, and it is okay to have the gate agent switch people around without any good reason, but as soon as a customer makes a reasonable request to get his or her original seat back (before the other passenger - who just got moved into a new seat 20 minutes prior - even knows of their new seat), apparently seat reservations become sacrosanct.