I think the point of bringing up hurricane Dorian is the size/strength. It's not unique by itself but cat 4/5's are at an upward trend[1]. Also take a look at hurricane Barry[2] this year. It's a disturbance that came out of the continental US, became a hurricane in the gulf, and came back to strike the US.
[1] https://www.gfdl.noaa.gov/wp-content/uploads/pix/user_images... [2] https://en.wikipedia.org/wiki/Hurricane_Barry_(2019)#/media/...