My view of this event as a non-EMH-guest:
I arrived at MK after work about 615. Crowds were extremely low - spring break is definitely over. I saw 1 couple with credentials about 6:30 coming in, but no more really until after fireworks (I'm sure they were out. But with the low crowds, I was averaging about 15 minutes per ride so I wasn't paying too much attention)
After Wishes I made my way over to Tomorrowland for the last 40 minutes of regular park hours. In that time I was able to ride Space, Little Mermaid, and Haunted Mansion. NFL was deserted, There were maybe 10 people in my stretching room in HM. Overall, the park was extremely empty. I saw Peter Pan marked as 20 minutes, I probably could have gotten my own boat on Small World. I didn't check out 7DMT, but based on the complete lack of people I would guess that it was a pretty short wait at that point too.
I got out of HM a few minutes after 11, so everything was officially EMH. I saw 4 people walking towards HM, a few waiting in Liberty Square for MSEP, but other than that I didn't see any credentials (I was in Liberty square which has no attractions, so that's probably why). After watching the parade, I started to head towards the exit at 11:30. There weren't any checkpoints to see if I had credentials (I could have easily wandered the park unlike the parties). Walking down Main Street, Casey's and Starbucks were the only food open - Casey's was blocked off to non-EMH guests, and I saw a group get turned away.
The stores were supposed to have a hard close at 11, but they all seemed to be open to everyone - every door was open and there were no CMs checking credentials.
I left the park about 11:45. My overall impression was that it felt like a standard off-season after-wishes evening, and the event crowd didn't add anything noticeable. Even after the official check-in time, I was still averaging 15 minutes a ride.