I received a message from AA that my fight has been delayed. My connection time was already short and I'm not sure I can make the connection now. I've missed the connection before because of a flight delay.

AA didn't give a reason for the delay. Maybe it's weather, maybe it's mechanical, or something else.

If I have an economy ticket (non-changeable), will AA allow for a change if I think that I won't make the connection?

If they won't allow for a change and I can't make the connection will they pay for a hotel? If so, how many hours would the next flight need to be to 'qualify' for the AA-paid hotel?

The answers to your questions depend partly on your routing. Where are you originating?

If you miss the connection, what is the next available flight showing up on aa.com?

The last time I had a similar situation a DFW to LAX/LAX to LIH flight delayed multiple times but finally cancelled well after dark. Perhaps because it was so late on a bad weather day AA sent out three of the most together GA's ever to the gate, rather than sending everyone to a rebooking line.

The default was being rebooked onto a similar connection the next day, but if you had another idea they were all ears. We asked for DFW to HNL/HNL to LIH on Hawaiian, which would get us to our somewhat remote hotel well before dark rather than after.

It was entered as an online ticket request. But, she did comment first that "She could not force Hawaiian to pick up the booking". But apparently they did. She handed us the new boarding passes. Followed by a comment "they don't always accept the booking so quickly".

I'm not sure if that is relevant or not. But it did appear the alternative carrier could decline.

Generally it has to be overnight (and not caused by weather)

Flight CLT-EWR yesterday was held 4 hours on runway. Mother + 2 six-year-olds were shaken up badly. How to go about compensation?

Highly unlikely that an aircraft was blocking a runway for four hours at CLT.

DOT rule re: tarmac delays can be found here:

https://www.transportation.gov/indiv.../tarmac-delays

What was the reason for the delay? Why were the passengers "shaken up badly"?

Northeast delay today Memorial Day.

AA delay times not up-to-date realistic.

On 4772 LGA-YUL. Incoming is 4524 (MSP-LGA) which got diverted to PIT.

AA updated 4772 delay by 2 hours once PIT-LGA left the gate but due to subsequent EDCT delay, PIT-LGA went back to the gate. No subsequent updates to 4772.

I think AA is a bit sneaky here. Under Canada passenger rights, they are to rebook on other airline for delays in excess of 3 hours even if outside of airline control. AA is keeping the delay as 2h when it is not realistic for PIT-LGA to make it into LGA. Meanwhile AC flight is delayed by mere 45 min which AA is unwilling to rebook.... until it was too late to be booked on the AC flight.

You're giving AA far too much credit. It's likely just the classic rolling delAAy

I get the rolling delay; outside of AA control due to FAA pushing the EDCT.

The problem is AA didn't roll the delay sooner despite FAA publishing delayed wheels up and the PIT-LGA pilot opting to return the gate (listening on PIT ATC and monitoring aircraft movement on flightradar) instead of waiting on the tarmac.

If AA did roll the delay sooner, I would have got AA to book on AC before AC's cutoff.

This is how unrealistic/uncoordinated the flight times are when delays are in play.

Screenshot 1 - AA4772 LGA-YUL - delayed to 6:35PM Eastern.
Screenshot 2 - Incoming aircraft - AA4524 PIT-LGA flight time is 15 minutes - departs 6PM arrives LGA 6:15PM
Screenshot 3 - FAA EDCT for PIT-LGA is 22:44 ZULU (6:44PM)

What's especially confusing about the PIT-LGA flight is that AA.com shows it being scheduled for a 1 minute flight time. It's as though it thinks PIT and LGA are in different time zones.

Per the OP's questions...

And they won't. I always go to Expertflyer to check the flight status and accompanying remarks. If they indicate an AA controllable reason I take a screen shot for future reference. This is a subscription service.

Yes. Get the AA app. Once it is likely you'll miss a connection the app does a good job of offering you alternatives. They will all be AA flights, however. If the delay is AA's fault and there is a non-AA alternative you need to work with a live agent to get that, and even then you may need to push.

Yes, if the delay was within AA's control (not weather or ATC) and the next available flight is the next day. Otherwise you're on your own. Travel insurance or some credit cards may reimburse you for the hotel and other expenses.

Passengers were never offered to disembark, once boarded on-time and door closed. Held on plane 4 hours before finally flying off, with no explanation or projection. This mother and kids haven't flown before, and all uncertainty took the best of them. Were told to contact airline later for compensation. Catch22: mother isn't really capable of these affairs in English. And what attorney would take a small case...Any advice appreciated

100% Agree that you need to have a backup plan working as soon as you see your connection is at risk. Look for alternatives on AA, within OneWorld, and on other airlines. Call AA and talk with a live agent and request re-booking on your preferred alternatives. Also, check with any agents at boarding gate or check-in counter and see what they can do. They may have better knowledge or experience with your airport's AA operation and how it best manages its IRROPS (which other airlines/flights have best availability).

My recent experience was this:
AA ATL-DFW-BCN

• Incoming a/c from DFW was delayed by something, unsure if Wx or Mx. We had a 90 minute connection at DFW which was eroding fast with every update.
• Eventually it became clear that DFW-BCN was not possible and rebooking was needed.
• AA app offered a few options out of DFW and others by connecting to MIA, staying on AA metal or Iberia through MAD.
• I called AA and got rebooked on BA's ATL-LHR with onward connection LHR-BCN leaving 4hrs after arrival at LHR. We wanted to get across the Atlantic that night and minimize delay getting to BCN.
• Subsequently spoke with AA check-in agent about getting on DL nonstop ATL-BCN, and they tried, but it had just checked in full or DL cleared all the non-revs prior to shutting the door. AAgent also checked ATL-AMS and ATL-CDG on SkyTeam (DL, KL, AF) but those were either full or had no better arrival time at BCN.
• We stuck it out with BA and got to BCN by 8pm the next day (after BA had their own Mx. issue at LHR)

So, check your options, get re-booked by using the app or live phone agent, and keep trying to improve your re-booking by working with local agents if possible.

An off-topic data point: on morning of flight, passengers were offered to volunteer (for $525 voucher or ?) to give up seat on this overbooked flight. Then gates changed twice, which was also quite a schlep with stroller and carry-ons