Disney is disclaiming all risks related to COVID-19. Imagine if Disney disclaimed all risks for anyone entering their park for anything. That would mean that a broken ride that hurts or kills someone is no problem. I believe that Disney is trying to bark people into not suing if something goes wrong. Which is classless. Under Florida law they cannot disclaim all liability - they know that.
I guess I read the language a bit differently than the OP. The operative language says this: "By visiting Disney Springs you voluntarily assume all risks related to exposure to COVID-19." The OP is emphasizing the "all risks" part of the sentence, where if you emphasize the "exposure" section, I believe it changes the meaning of that sentence a bit. Disney is not disclaiming its liability as to the acts/failure to act, but as to the results of those acts, i.e. hospitalization, permanent disability, or even death. This sentence is immediately preceded by a description of the danger of Covid-19, what could happen, and who is most vulnerable.
In a similar vein, everyone gets all up in arms about the "hot coffee" case, but in actuality, McDonalds really was in the wrong. They intentionally kept the coffee at 195-205 degrees based on the assumption that people would get the coffee and bring it back to their home or office before drinking it (most people's preferred drinking temperature is between 125 - 155 degrees). However, they never communicated that assumption to customers. They admitted during the trial that it was a hazard. They had also received several hundred complaints from customers that the coffee was too hot but didn't do anything to either change its practices or educate its customers. As an aside, the original jury verdict awarding the plaintiff (a 79 year-old grandmother who suffered 3rd degree burns to her legs and genitals and who readily acknowledged that the spill was her fault) $2.9M was later reduced to $600K. McDonalds also changed how hot it kept its coffee.
A prior poster mentioned reasonableness. In the hot coffee case, it was reasonable that the plaintiff could potentially spill coffee on herself, which she admitted was her fault. It was reasonable that someone might be injured as a result, most likely first degree burns like if you spill coffee on yourself at home. What was unreasonable was the extent of her injuries. McDonalds knew the risks but did not communicate them to customers. Here, Disney is communicating not only the risks but also the possible outcomes.
No person can assume the risks of intentional acts (like if a Disney employee either knowingly spreads Covid-19 or didn't intentionally properly follow safety protocols). Assumption of risk only applies to negligent acts or failure to act. If the coffee maker at that Albuquerque McDonalds had just gone on the fritz that one day when the woman got her scalding hot coffee, it might have been a different story. As it was, McDonalds' intentional acts, knowledge of its hazards, and failure to change its behavior were part of that jury verdict. My reading of that disclaimer is that Disney is not only communicating the guests' responsibility but also the potential results of such exposure.