Same here, I was scheduled on AA MIA-LGA for tomorrow morning, they canceled, and all they offer is a rescheduled ticket with a stop through ORD or DFW, I declined, and booked Delta MIA-LGA Tuesday morning (and for backup FLL-LGA Wednesday morning).
Im not holding my breath on AA covering the new (expensive!) Delta ticket, but I hope I’ll be able to convert AA’s canceled ticket from “Flight Credit” to a full refund.