The EV charger debate is a mildy interesting one. I had thought that Epic would have used a similar approach to the DLP parking lot with solar panels for car charging and also providing well needed shade from the Florida sun.
But the new plot is being built with future expansion in mind and no doubt they will adopt the same process as the current Orlando resort if they decide to expand by building a multi story parking garage and building another park on the parking lot.
As for how many chargers to install, it's a near impossible guess. You don't know how many EVs there will be nor how battery technology or efficiency will improve, or even if a new technology will be introduced.