Then the nukes won't go off.
They require ongoing maintenance and replacement of scarce material (such as tritium, which costs about $50,000 a gram).
Two things about that: 9/11 happened on 9/11 because that is when the assets could be put in place. There were delays. It might have happened sooner. No significance to the date.
The second thing is it took years to plan 9/11 and the Cole bombing, the latter of which was delayed for something like a year due to the right ships not being in the right place.
Not really possible to say one way or the other. You can't say "It would have happened already." And you can't count on numerology.