I agree completely. Unfortunately this is not the world we live in--the DoT rules on this are clear and not so sympathetic to class of service distinctions.

In this particular case, what does the phone agent see?
I'm going to guess the agent may see flight oversold, seat to be assigned at airport.
I'm not sure on what basis the agent could have done anything other than voluntary re-ticketing, which is what it seems they were trying to do for the OP and therefore checking aaward inventory.
On a revenue ticket, the agent would have offered change fee + current price ticket, since this is not IRROPS at the point one calls.

In other words, does an oversold cabin give grounds to a free re-routing with an agent on the phone? The standard answer will be "go to the airport".

Again, agreed completely, which is why with high probably this was going to be a cluster for the OP, and it's a miracle it wasn't. Anybody touching this record before boarding at PHL is a customer service gesture--which folks like JonNYC can sometimes make happen. Once boarding at PHL, options are severely limited and the policies are not in the OP's favor. That is entirely my point.

I know people cancel for whatever reason all the time, but is it possible that any of the cancellations (in J or Y) were people contacted by AA to take a different flight (perhaps based on their actual end-destination and offering them a better route to get to their destination)? I know US back in the day would call me asking me about taking alternative options for whatever reason (usually overbooked). I could say this thread might have caused some of that behind the scenes efforts, but I don't have that insight.

It does appear the now blocked seats were mistakenly offered for inventory for this flight (whether or not the crew rest need is necessary or not, that is not my call).

I think from threads like this, we all are reminded on how much we need to proactively find options for such issues. As such, I have changed to/from airports, days of travel, etc. when I have dealt with situations where I could not travel as scheduled for whatever reason. If that is the value of this thread, not a bad deal.

Count me in the remaining 10% pool that does.

Most people enjoyed it-- who forced you??

Much like GoT, I enjoyed it until the disappointingly tame ending.

I for one, learned some new lingo and strategies in case this ever happens to me.

Very educational thread.

There was a wealth of information in this thread. Thank you to the experts for suggestions and recommendation to help these folks. I feel for this couple and what they went through and am happy for their miracle ending.

But as many others have said -- it begs the question how many people does this happen to that don't come to FF --- probably lots --- and how would AA resolve this situation if there's not a fortuitous cancellation or mixed connection? If push had come to shove came at the counter.

Unfortunately we'll never know for sure. Like the ending to The Sopranos.

This is the optimistic way of seeing it. We also (re) learned, that (a) AA is incompetent, (b) they don't care to fix their own mistakes, but rather have you squirm until the gate, to protect their revenue, (c) you will waste a lot of time on the phone (several hours) trying to fix their own mistakes, but likely to no avail, (d) there is no clear way to fix these issues, and (e) it will take either a miracle to resolve your issue (but still you have wasted your time and energy and stress, like the OP), or it may not get resolved and you will fly coach and they may give you a handful of miles for compensation (which you will also have to ask for).
All I am saying is that if they were competent and/or cared to fix their own mistakes, we wouldn't have to learn anything here...

Just to clear up one thing that is still unclear for me...

It seems that each time OP called AA he was told this needed to be sorted at the airport. It also seems that OP's plans really needed him to get directly to EDI. Let's say that this was me and I'm on business and I'm flexible. That means I can fly to an alternate destination (MAN was suggested) and my employer would pay for whatever route needed to get me from MAN to EDI (perhaps by train).

Would AA have made that change over the phone to MAN given this situation? I guess I'm asking is if I'm booked in J and it's oversold will AA make the change for me in advance rather than me showing up to the airport early to see if they would make the change?

Yes i remember getting calls about taking a more direct routing on numerous occasions.
I was usually re-qualifying for Chairman Preferred so would pick some interesting segments.

Those were the good old days for sure

Can't thank JonNYC enough. His notification that the seats were open and that we had been assigned to them couldnt have came at a better time as we were most likely going to end up being rerouted with multiple layovers and a significantly delayed arrival time.

AA gate agents confirmed our names are assigned to the seats and they now show up in the app. They even showed me the screen they see (but wouldn't let me take a picture as it had other passenger names on it). However, DTW for some reason cannot print BPs with seats on them, said it has to be done at PHL. My PHL - EDI BP says a seat will be assigned at the gate... Hopefully this isnt AA playing games and we'll have a smooth process in PH. Will update once we have final BPs.

I sincerely apologize I wasn't able to be a better test subject ;) . 36 hours of stress but I learned a ton from all of you!