You never know until the storm hits how its path will affect land. Right now, it's a tropical depression and is forecasted to park itself off the coast and bring a lot of rain for multiple days. Julia has been labelled "weirdest' tropical storm of the year. But weather can change and so it could do more or less damage than predicted.
Even if a storm fizzles out as soon as it hits land, it should still be treated as a threat. Nature is unpredictable and it is in our best interests to prepare for the worst possible outcome. When a storm approaches, everyone in its path needs to take measures to protect themselves and their families, no matter how weak or strong the storm is.
Yes, tropical storm Julia is a significant threat because many people will be in its path. During major weather events we should always take precautions. Without the necessary safety precautions in place, we will be unprepared. Even if the storm fizzles out, it is better to treat it as a major threat in the first place.
Tropical storm Julia is only a significant threat to the extent that it can cause widespread damage to the landmass over which it goes. Otherwise, it will have no other effect as it quickly moves off the coast and further to the sea. Any storm of the significance should be approached with caution.