Hi! Newbie here. Within the past week a flight I have in July from PHL to MSY has been changed twice. The first change is arriving in New Orleans at noon, when I was previously arriving at 6pm (no big deal-- extra time in my favorite city!), but the second change was then an aircraft switch from an Airbus A319 (128 seats) to an Abraer ERJ-175 (72 seats). Has this ever happened to anyone? Is this normal?