I have travel upcoming in July- PHL-ORD-YYC and return

In my weekly check for changes, I noticed several minor time changes on the first three flights but on the last leg (ORD-PHL) I've been put on an earlier flight, which lowers connection time from 2 hours 25 minutes to 50 minutes (the itinerary even states "note short connection time"). I know 50 minutes is a "legal" connection at ORD but doesn't give me much time if the YYC-ORD flight is delayed. (All flights are on AA) My other choice is a three hour connection. When booking I avoided a one-hour connection for the initial outbound leg (PHL-ORD) , but an outbound missed connection is more concerning, as I am meeting a tour group in Calgary. I'm scheduled to get home Thursday and am not due back to work until the following Monday, so a delay getting home is less of problem. If I take the 50 minute connection, i obviously get home a little earlier (10:05 PM vs 11:53 PM), which may make getting an Uber/Lyft a little earlier.

Question is it worth the trouble to change to the later flight to have a longer connection? Time change is less than 2 hours, but new itinerary switches last leg from an A319 to a 737-8 (not Max-8), so there is a change in equipment. Also, I know the itinerary will likely change again before the travel date, but by the same token, I don't want to count on it.