I don't know about Bimbo Breads specifically, but I do know a lot of manufacturing plants will produce several products on the same production line, in batches.

A brewery that produces several types of beer would have separate fermentation tanks for each one - but might only have one bottling/canning line.

I wouldn't be surprised if bread manufacturing was similar - you might produce 8 different types of bread, but only have one bagging machine.

Of course the entire plant would be deep-cleaned once per day. But you'd be switching between products 8 times per day, so there's not time for an hour-long cleaning every time.