Of course the Disney parks are a possible target, they've been aware of this since 9/11. Any place which is high profile and attracts large numbers of people in a lesure capacity is.
Apprently the Orlando nightclub shooter scoped out Disney Springs as a possible target for his atrocity. Disney Springs isn't a theme park, it's an outdoor mall and restaurant complex which makes it a very "soft" target as it dose not have the security level the theme parks have.