Hurricane prediction is a science, thus there can be changes.
Hurricane Dorian's track, as in direction, appears to be changing a bit, sparing Florida from a direct hit, but not from some significant impacts.
As Dorian movement predictions track the hurricane more to the north, everyone in Florida cannot breathe a sigh of relief — just yet. Two aspects of the storm could still have huge impacts to Floridians.
First there is the storm surge. Even with the storm just off the coast, the counter-clockwise motion of the winds will bring a strong storm surge to the Florida coast. Worse yet, king tides are coinciding with the arrival of Dorian, which means that any storm surge will be much more significant. The same thing happened in New York City for Superstorm Sandy, with a wall of water entering the city, swamping much of the city's infrastructure.
The other issue is rainfall. I've read multiple reports about how the storm might "stall" and stop moving north. That will lead to super-flooding. Totals can't be predicted, but the flooding we saw in Houston is an example of what happened with Hurricane Harvey. Areas of the city that had never flooded (and they have had frequent and severe flooding in recent years) flooded.
With climate change beginning to have its impacts, there have been calls to perhaps change how hurricanes are rated. Currently it is only wind speed that guides the categories. One new item being discussed is adding a "category 6" for even higher wind speeds, and including a forecast for rainfall — which is becoming a bigger factor in some storms' impact.