On the Times Guide,"Park Open" refers to "regular" Park Open(8:00 AM or 9:00 AM in this TG)-it does not refer to AM EMH open.
Fantasyland opens for AM EMH so,"coincendentally","Park Open" for Ariel does mean Park Open for AM EMH also,BUT it DOESN'T mean AM EMH Park Open for Jingle Cruise,Tiki Room,etc.