I think a way for fast food places to stay consistent would be to release more limited-edition holiday releases. If I was a person on the marketing team, these three ideas are what I would push.
If you sell coffee, you should have a holiday option. Most fast-food places that do breakfast and coffee don’t really switch up the flavors. You might get lucky with a peppermint mocha. Having flavors like gingerbread, something with extra chocolate, maybe even something apple-related would bring in customers. Especially ones who don’t buy coffee from Panera or Starbucks. Specialty hot chocolate would be nice to see as well.
A lot of international chains have something with gravy but for some reason, America does not. Dairy Queen is the only place that serves it as a dipping sauce. There could be a meatloaf style sandwich for the holidays. Already have the ground beef there. Wendy’s could serve gravy as an option for their baked potato. Gravy on a chicken sandwich. Or let customers create their own version of biscuits and gravy.
Holiday shaped nuggets-
I just think this would be a fun change-up. Stars are pretty easy, maybe trees or candy cane shapes too. It’s not like nuggets are being handmade in the store so why not send some with a theme. You can get cartoon shaped nuggets from the store, so why not from McDonald’s too? Just make sure it can fit into the sauce containers.