Today, no parks closed to capacity.
Yesterday and Xmas, MK closed to Phase A, which still confuses me a bit (I've seen conflicting info). All I know for sure is that if you're staying at a Disney Hotel, you'll be admitted under this designation. Beyond Phase A, no one really knows at this point.
While phase 4 (or its equivalent) is possible at MK on NYE, I will say it hasn't happened in recent years. Now, before you all who claim to have been there and know it closed call me a liar, understand that, in the parks, a lot of misinformation is spread. Generally, the only CMs who know the most up-to-date info are the ones manning the entrances, ticket booths, and guest services. I've been there too during this time and have heard that the park's fully closed from CMs only to see guests still entering the park. When I asked a Main Entrance CM, I got something to the tune of "we're only admitting resort guests." Last year, MK remained open all day to Disney Resort Guests on NYE.
Here's the strict data from last year's NYE per
WDWMAGIC (it gets this info from the Hub, so it's very accurate):
9:40am - MK closed to Phase 2
11:04am - MK closure elevated to Phase 3
8:00pm - MK reopens to all
Here's the difference between the two phases:
PHASE TWO Admission is limited to:
Disney Resort Guests (including the Walt Disney World Swan and Dolphin, and guests arriving by bus from the Hotel Plaza Boulevard hotels)
Annual, Premier and Premium Annual Passholders
Guests with Hopper tickets coming from another park
Guests re-entering the park
Guests with dining reservations
Magic Kingdom Guests with reservations for Bibbidi Bobbidi Boutique or The Pirates League
Guests using Walt Disney World Resort Transportation will be admitted.
Guests with pre-purchased 1 day Magic Kingdom tickets
PHASE THREE Admission is limited to:
Disney Resort Guests (including the Walt Disney World Swan and Dolphin, and guests arriving by bus from the Hotel Plaza Boulevard hotels)
Annual, Premier and Premium Annual Passholders
Guests with dining reservations
Magic Kingdom Guests with reservations for Bibbidi Bobbidi Boutique or The Pirates League
Again, I'd still have a plan b, but hope that helps a bit. Mind you, this could all change with these new phases.