I'll never understand where they get these dates from. What is going to be different between June and November that doesn't allow mass gatherings in June but does in November? I'll have to use my imagination but it makes absolutely no sense from the standpoint of an infectious disease that won't have a vaccine in that time frame.
The difference is herd immunity. You should read up on it.
Large gatherings create the possibility for the virus to spread quickly. By not allowing large gatherings the virus will continue to spread, but more slowly so that we don't overwhelm our medical system. Everyday more of us are infected and more of us recover creating the all-important herd immunity. The virus cannot survive when either a vaccine is created or enough of us have immunity and can no longer host it.
The idea behind reopening is that you slowly open up while still controlling the spread. We now have a better understanding of our capabilities and most medical systems are not overrun, so you test it out by creating situations that will allow for the spread to happen more quickly, but still controlled.
The infection rates in some areas of the country are low, but we need to accelerate them to get the all-important "herd immunity".
I suspect that Disney Parks are going to be closed for a long time. When some of you say June or July I laugh. Shanghai Disneyland Park is still closed. When that park reopens that will give us a better timeframe of how long it will take.
The other factor is our elected officials. I fully suspect that Florida parks will be able to open far before California, even if the infection rate in California is lower. The governor of California through his own statements appears unwilling to loosen the reins.
Another factor is when can the parks reopen and operate without incurring a loss. All of this talk of queue changes, elimination of fireworks, shows, and more is pure speculation from fans. The parks can operate at a reduced capacity, but how much?
If Disney opens and the people don't show up then would they be better off remaining closed?