u/Buckminster419

We were supposed to be flying today but due to air traffic control delays, my daughter and I were rebooked for tomorrow and our seats are now separated. The agent said "Please don't worry, I have documented this information and sent it to the airport. You will just need to mention this to the gate agent, and the cabin crew will assign you seats together without any charges." Is this complete BS? Should I just eat the $200 to get us to Economy Plus so we can sit together? Or hope that it will all work out? I was a bit surprised that the agent said the cabin crew would be assigning us seats...that doesn't quite seem right.