i suspect it will be a bigger financial hit to them if they have to close again than if they simply stayed closed longer. on a smaller scale, by way of example-we had a local bar/restaurant reopen recently and within a few weeks a covid outbreak was traced to it (group of people not following the place's social distancing-all got it, one server who served them and had tested negative immediately prior to reopening ended up coming down with it as well). they initially planned to close, re-sanitize, make sure remaining staff was clear. then they ran the numbers. all that food they had restocked would have to be tossed/replaced as well as the cost of re sanitizing when the same thing could happen the same night they reopened. they decided to stay closed for now and several other restaurant/bars cancelled plans to transition from to go to open dining. at the scale of all the food and other perishables disney must have to bring in, the size of their properties and cost to sanitize if there's a large scale outbreak. that would be hard for any company to recover from.
i also think about the employees-it's no secret how difficult the unemployment process has been in most states. think about what a pain/financial hardship it would be to go back to work, have you unemployment case close and then a few weeks or a month later have to turn around, reestablish your claim and then wait god knows how long to get your first check