I have actually had pizza at the Pentagon. True, it was almost 30 years ago, and it tasted like federal-cafeteria pizza, but it was edible and I'm still alive.
I doubt that's it. Artificial demand just adds noise to the signal, it doesn't eliminate it. It seems more likely that they've just decided that knowing the Pentagon is working on something without additional details isn't a very useful signal for adversaries.
I was about to make this same comment - this data might've been more useful for say, the soviets, when they were the only major threat that the US was actively dealing with, so they could have some guarantee that if they spotted a ton of pizzas being ordered to the pentagon, they could be fairly sure it would be something to relevant to them.
One of the examples was the night before the '91 Desert Storm started. For those that weren't around, there was a huge build up operation called Desert Shield and only became Desert Storm when they started shooting. It's not like that was a secret, and the Iraqis could have seen this data and not be surprised when the bombs start falling immediately after the pizza surge.
If you were bin Laden, maybe you might not have been caught unawares helicopters were about to crash in your garden. It's not like you didn't know they were looking for you.
I can't think of someone that the Pentagon or other agencies that this applies to that their adversaries would not know they were the adversary. This might be more relevant than you might think
Plus when it’s time to go Mutually Assured Destruction, ie to those capable of attacking the US mainland, I’m going to assume they would be doing all this from whatever the successor to Mt Weather is.