It's worse than reckless. They make not-knowing part of their operating model.
And they make sure nobody else with power and influence does too much knowing either. Silos, stay in your lane, don't ask questions about how your department's KPIs mesh with the next one over, or what conclusions might be inferred.
At her level of responsibility she'd better know. Whatever the case, she's either deceitful or incompetent. Neither answer is flattering or acceptable.
There's always the chance one could have ridden fake-it-till-you-make-it long enough for the engineers to solve the underlying issues...
There are some leaders who are extremely good at convincing you about the importance of belief in a particular thing to the point where you avoid even thinking up those questions - if they are ever cornered (and they rarely allow it to get to that point) they will wriggle endlessly rather than responding to a line of inquiry that bursts the collective bubble.
Do they know? It's hard to argue about their internal motivations.