Cat 4 expected now? Wow this thing is getting big.
It won't be Disney. It will be the areas around Disney.
That's where people will notice it, absolutely. Disney the day after you won't be able to tell. But those around, especially those still cleaning up from Michael a bit, may have some issues. So much of it depends on the exact storm track. But honestly, the biggest deals will be downed trees and power lines, and some roof damage. On the coast will be a much bigger deal, and that's where you'll see the real damage. But as you make it inland and around Orlando that will go down.
I have no doubt they'll do amazing work. But hurricanes being hurricanes, nature will do the inconveniencing. Disney will certainly lessen the inconveniences by a considerable degree.
Disney is probably the safest place to be during a hurricane. Outside of staying in the resort for a full day and the parks possibly being closed Monday more than likely, which is an inconvenience, guests at Disney likely may barely realize there is a storm blowing. Disney has in the past even brought food to people's rooms (sandwiches and things as I recall).
While I was in Florida, I went through Charley (landfall 25 miles south of me), Frances (eye went right over us) Jeanne (another eye over us) in Tampa, then Wilma and numerous tropical storms at Disney. Those that haven't been through a hurricane, especially in Florida, don't understand- that state is built for them, and most of them make a bit of a mess for a couple of days similar to what an ice storm does up north. (honestly the damage levels and types are really similar having dealt with both).
Will it make a mess? yes, especially on the coast, lesser so as you get inland. Is it dangerous? yes, especially if you're stupid and don't leave the coast where it could hit. But if you're inland what it means for the most part is, usually, a couple of days of camping inside, perhaps without power, and some yard cleanup afterwards.
And hopefully this one won't be like Irma was. That one was the rare exception that created a mess through the whole state.