You are correct. And because I never delete anything, I was able to find my 2016 confirmation and the wording there was:
Guests may check-in at the Will Call booth outside the magic Kingdom® park main entrance from 4:00pm- 7:00pm. Starting at 7:30pm, Guests will check-in at the parade viewing area located by the flag pole in Town Square, inside the park after you pass under the train station. Guests will receive a credential for identification upon check-in.
If Guests miss the parade viewing, they may check-in at Tomorrowland Terrace 9:30pm
It was then followed by an itinerary email 1 week before the party with the following, more detailed info:
Your Itinerary
4:00 PM - 7:00 PM:
Check-in at Guest Relations outside the Magic Kingdom® Park main entrance.
Pick up your credentials at the Guest Relations window, also known as Will Call, outside of the Magic Kingdom® Park main entrance on the east side.
Guests who miss the parade viewing can check-in for the Dessert Party directly at Tomorrowland Terrace at 9:30 PM.
7:30 PM
Gather at Your Special Parade Viewing Area
Meet fellow spirits by the flag pole in the middle of Town Square, located inside the Park once you pass under Walt Disney World Railroad train station.
8:35 PM
Experience Mickey’s “Boo-To-You” Halloween Parade
Experience frightful floats and kooky-spooky characters as you watch from an exclusive reserved location on Main Street, U.S.A® Area
9:00 PM
Enjoy Dessert Party and Happy HalloWishes Fireworks Viewing
You’ll be escorted with the other ghosts and goblins to the Tomorrowland Terrace and enjoy a magical display of fireworks while you feast on Halloween-themed sweet treats and specialty beverages.