This depends on why you think your puppy is going to mature into a fearful dog. If there's mostly a genetic component, Puppy Culture cannot change the genetic tendencies of a dog -but early training can mitigate some fearful tendencies.
However, if this tendency is due to lack of positive socialization and bad learning experiences, then there's a good chance that using Puppy Culture principles can help this fearful behavior.
To complicate things, many dogs can be fearful from a combination of things. This can depend greatly on when you start using these principles (at birth versus 12 weeks for example) and how you apply these principles, but generally we see improvement in these traits.
As always, your mileage may vary. Some people may see no change, some may see dramatic change. It's something you likely won't know until you've done it with a few litters. However there's no harm in trying these protocols!