So far, it seems the answer is "yes." The fine print reads "up to 3 hours" for evening EMH, but in all the times we've experienced it this year, it has been 3 hours. And, even during the thick of Spring Break, we didn't have an EMH morning start more than 1 hour before regular opening.
There may have been some exceptions, but we've not experienced them yet.
Anyone else miss the 90 minute EE back in the day?