Don't they just heat up frozen/pre-made bread? I don't know...just I don't think they have enough room to be a real bakery. Also, corporate financials would have centralized that a long time ago.
Frozen dough doesn't come out the same, nor does reheated pre-baked bread. It's fresh it just isn't made from scratch there in the store.
There's a couple dozen fresh dough facilities scattered throughout the US that serve all of these restaurants that need fresh bread, but without the cost of paying someone to mix flour locally.
The thing you buy at 6am (or 6pm, lol) was in an oven or a mixer (depending on whether the chain in question is baking on site or at the hub) at 12am that morning and on a truck at 3:30.