In most cities a reserved dog can be given room. You cross the street, you take the wide side of the path, you angle away from an oncoming group. South of Broad and along King Street those options frequently do not exist — buildings sit hard on the property line, the sidewalk is narrow, and carriage tours and walking tours move through in clusters all day. Passing a group means passing within arm's reach of it, ten or twenty times on a single walk.
The risk is not that the dog snaps. This breed is even-tempered and genuinely good with children. The risk is attrition: a dog that spends two years being reached for by strangers it did not choose to meet gradually stops finding walks pleasant, and that is how an even temperament is worn down rather than how it fails outright.
The management is cheap and mostly about routing. Walk the peninsula early, before the tour groups start moving. Use Hampton Park and the residential streets north of the historic core for daily mileage, and save the crowded blocks for times when you actively want the socialisation. A dog rated 4 out of 5 on trainability learns a reliable 'behind me' position quickly, and that position is worth more here than any amount of obedience polish.