Under Florida law, timeshares cannot selectively restrict access to resort amenities if they are funded by association dues. Since all owners are paying for parking lot maintenance, DVC cannot bar one group (e.g. resale buyers) from using the amenity while others are permitted.
Items like the Epcot lounge and Moonlight Magic events are fully funded by Disney Vacation Development as a marketing expense, NOT paid for by member dues. Therefore, DVD/DVC is able impose its own participation requirements in those situations.
EDIT: That said, the writing is on the wall with regard to DVC's future intent. Resale buyers should expect that they will be excluded from true "perks", both now and in the future. (Free parking does not qualify as a "perk".)