Part of me says that it would be a really bad move for them to miss initial event registration. The other part of me says that if the timing was really that close they would have just made it into the catalog. A third part of me says, "Hello San Diego Comic Con."
It's worth noting that as per the other thread, the Starter Set is now mostly confirmed for July 15th. Which means the Barnes and Noble "leak" was correct. That information was released yesterday to retail stores.
We know that Dave Christ assured everyone that he had put in the descriptions of all the D&D events months ago to be sure that they were all ready to go when event registration happened. He tweeted that and he posted the same thing here on ENWorld.
We also know this exchange happened on Twitter just recently:
Martin Tideswell [MENTION=28]Martin[/MENTION]Tideswell May 11
Hello Dave and team [MENTION=6674266]Ba[/MENTION]ldmangames Do you know if the DnD events be up on the @Gen_Con events listing before next Sunday? Flying blind here!
Baldman Games [MENTION=6674266]Ba[/MENTION]ldmangames May 11
[MENTION=28]Martin[/MENTION]Tideswell @Gen_Con I have no answer for that I'm sorry. I really!!!!! hope they do but this is above my pay grade.
Martin Tideswell ‏ [MENTION=28]Martin[/MENTION]Tideswell May 11
[MENTION=6674266]Ba[/MENTION]ldmangames @Gen_Con Darn... Hard to plan anything else when we haven't seen this! Is the new edition of #DnD actually launching @Gen_Con?
Baldman Games [MENTION=6674266]Ba[/MENTION]ldmangames May 11
[MENTION=28]Martin[/MENTION]Tideswell @Gen_Con cannot answer that but hope to post a helpful update as soon as I get it approved.
It looks like Baldman Games(which is likely Dave Christ) has no idea why the events they entered aren't active on the GenCon website. Also, note that the wording he used when replying to the second question was "cannot answer that" rather than "I don't know" or something similar. I'm positive he knows the answer and isn't allowed to say. He's also waiting to hear from WOTC as to when he is allowed to post an update.
Honestly, I can think of only ONE reason why WOTC would wait to post those events: They are waiting for SOMETHING to happen before they post them. I assume that is because PR is trying to coordinate a couple of things happening at once, like an official announcement along with details going out to distributors and retailers and the events going live at the same time. However, there is the possibility that they ran into some problems with printing or shipments and are waiting to hear back from part of their supply chain before they can make an official announcement(since they might have to change the release date).
I'm positive that the delay has to have SOMETHING to do with the release of the books, however.