I can't help but think that they agreed to word this so similarly as a way to hint that the words have been put in their mouths. It's like what somebody that's being held hostage would do to make you understand that they can't talk freely.
Zuck likely saw the Page stmt before he+lawyers finished theirs, so it's not at all necessary to jump from "doesn't seem independently formulated" to "therefore govt handlers probably gave them a PR formula".
Anyway, what difference does the origin of the statement make? The companies are either trying to deceive us, or they aren't. What matters is what's being done to us. We're all powerless here except to let politicians know we're unhappy, will vote against, fund EFF, etc. "Gotcha" parsing of official statements is not an important tool in this fight.
Personally I find ridiculous the notion that proud public figures will feel less ashamed technically not lying than actually bald-faced lying. Either way, you've sacrificed public credibility. So the whole discussion of "is this really a denial?" is uninteresting to me.
"It's like what somebody that's being held hostage would do to make you understand that they can't talk freely."
Assuming it the program is classified, and assuming that Zuckerberg has a security clearance, then under federal law he would potentially be eligible for the death penalty if he were to confirm the existence of the program.