I don't have an explanation from AA as yet. The response I got from AA to my written letter only addressed another aspect of the letter and just ignored this (lesson learnt: if you send a letter to any airline, send a single focused question/complaint and nothing else and send separate letters if necesssary).

The gate agent (business/elite check in line) started with the normal processing but after entering my info on the screen simply said it is "closed". I said "huh?" and she noticed that the flight isn't departing until two hours later and went and spoke with a supervisor for at least 5 minutes. She came back and just said it is closed and she can put me on a flight the next day. No offer of anything.

I said that is not acceptable and that I needed to be back that day and asked if she can do anything else about it. At that point, she said that I am entitled to a $300 voucher for future AA flights as DOB compensation. That is it. No hotel, nothing else.

At that point I was more interested in getting back than getting bumped (for any reason) and getting compensated for it. I suggested that they put me on a BA flight instead. She at first said she couldn't possibly do it and when I insisted firmly, went and spoke to a supervisor again and finally issued a ticket for a BA flight that was departing right after the AA flight. The only other thing that I can think of that might have been a factor is that I had changed the date of the return flight a couple of days earlier.

Ironically, there was a non-elite line for the EWR flight that had at least 40-50 people waiting in it and being processed all this time so it couldn't have been fully checked-in by that time.

Oh well, I don't need to fly AA.