No breakin period specified by Ford per se. The closest we come to it is the 1,000 mile cautionary period when the vehicle is new. Although it doesn't usually take more than 200 miles (on the outside) fo rthe PCM to learn the proper adaptives, you could choose to wait out that 1,000 miles to be sure.
The trans is likely to be a remanufactured unit, not a new one, and supposedly "as good as new". IDK if it wears in the same as factory new tho.