it's really not that simple. For one that lives close, there is risk -- for ones that will only visit for Christmas, there might be limits.
You still need to have a park reservation. Someone visiting in DEC (for that quarter) might not have an issue making a reservation in advance, BUT, I do not know how many reservations one can have in advance. If it is a 10 day trip planned and one has a restriction of only 7 res at a time, well, risk comes back. For a local, when do you look in dates and still go for Thanksgiving, what do you tie up for NOV and when?
A visit to Disney is complicated -- soon for AP's not so much AFTER 2pm -- save MK where you might need to check into Epcot and hop to MK (if hopping is allowed for non-reservation folks.