You are correct, MGM will have an evening EMH on New Years Eve. It will be open to day guests until 1am and then it will have the EMH for resort guests from 1am-4am...
MK will have a morning EMH 7am-8am and then be open to everyone from 8am-1am.
Epcot is open from 8am to 1am for everyone.
AK will have a morning EMH 7am-8am and then be open from 8am-6pm for everyone.