Family Guy, and most Fox adult animation series sans Simpsons, maybe Bob's Burgers for the food concept alone and possibly Futurama (which was at Springs!) will never be seen in any capacity at any Disney Parks or experience.
Those three are safe, not much in those that wouldn't be seen in a PG-13 MCU or SW film sans some themes that can easily be toned down for parks representation/ignored all together.
Family Guy, American Dad, and whatever else are completely different monsters and operate on a more adult scale than what I feel Disney would be comfortable with. Deadpool is an exception due to the character being popular with teenagers and being relatively easy to tone down (even had a PG-13 film already!).
Some R rated properties, such as Alien and Predator, can be turned into theme park attractions and I can see Disney exploring these IPs due to their legacy and popularity along with making these attractions for the 13+ crowd. Something like the 'Nostromo' concept finally becoming reality would be an easy bone to throw.
But Family Guy in terms of its R-rating is more than the violence seen in Alien and Predator, it's the language and content seen in it. I don't expect it to ever touch the parks in any manner. I see Simpsons in the children's toy aisle at Target and Walmart, I even have a Homer on my work desk, I saw Alien and Predator toys in the children's toy aisle a few years back also, you'd never see Family Guy in those aisles, and to a greater extent, at a Disney park.