In my experience, Delta will almost always change your flight info a few times before you fly. Sometimes you receive an itinerary update, sometimes you learn about the changes when you log on to Delta.com and check your itinerary. So be sure to double-check everything a few days beforehand. FWIW, our issue with this may be that we frequently travel with Delta right after the first of the year, but IME we've had nary a trip where this HASN'T occurred.
Second, +1 to the Gold or Platinum Delta Skymiles AmEx for waiving the baggage fees, but I think you might have had to make the ressie with them. Before you get the card for that purpose, check to be sure you'll be able to take advantage of that perk.
Also +1 to the curbside check-in if available! We always, ALWAYS use this if it is available at the airport we're traveling from, and it has always been a huge time saver. You walk in and look at the line for the ticket counter and thank your lucky stars you don't have to do that!