Last year my wife and son went to Orlando from London with American Air. Travel agent sat us all together, and I checked the app every day to make sure they were still selected. Then one day they got deleted, AA were adamant the travel agent did it. I doubt it! Oh well, we were all separated on that flight.
This year we have booked the same trip. Once again, two weeks before travelling our seat selection has been deleted. AA again says it's the travel agent. No more seats together available.
Not very happy about this. I feel a bit targeted.. 
I don't want to sound like a whiner, I am aware that the seats that are free to reserve when you book an airline ticket can be moved. I'm really just wanting to know if this has happened to anyone else?