MNSSHP is still on the schedule. It's easy enough to cancel closer to event dates. If they can don't safely and profit enough it'd be silly to not have the event as a second step of something familiar. For a while it could be the only way to see MK after dark, and that's both sad and what marketing dreams are made of.
Again speculating here, but F&W sounds like a headache with social distancing requirements. 1) I can't imagine booth lines working that well. 2) while it could work with lower capacities, they won't get near the same volume of sales that it might not be worth specialty booth expenses. 3) The function, drawing locals and guests to EPCOT in a "low" season just might not be needed when Disney may already have too many guests on the books. Maybe WS restaurants could run more specials and/or some serve past favorites, but the traditional F&W festival has so many question marks that it may not be a reasonable expense for a potentially modest revenue bump.