Thank you for your reply. Actually, though, for me, it is a bit tricky to understand. Everyone on this thread keeps citing things like they are policy, "no reservations at all between 6:30-7:00" or "reservations after 6:15 need a party ticket" but these policies don't seem to be anywhere on Disney's site. In playing with the app and website ADR system, sometimes you get a message, sometimes not. Nothing is consistent that I can find.
There was no hard ticket caveat on booking 7:00 on either the app or via the phone CM's system.
The phone CM (notoriously unreliable, I know, but I'm just as inclined to trust her as anyone else) said that there is no hard-ticket requirement on reservations that she can see up until the 7:05 time. According to her, they will allow you to eat and escort you out if you don't have a ticket as long as it's before then, including 7:00.
She also said that dinner on her system (and on the app, for that matter) is listed until 10:30pm, not 6:30pm, as some have stated here. It's possible we are looking in different places, but my point is that there is no consistency. And no official, consistent word on the matter.
HOWEVER, the confirmation email just came through and it DOES say that you have to have hard tickets. So I've cancelled the ADR. But again, this just reflects the lack of consistency.
So, no, it is not as easy as that.
Note: Just so the timeline is clear, I posted my question here right after finding the ADR time on the app. I then immediately called to see what they would say. Last, I got the email. In the meantime, I received the response here that I am now replying to.