I'd prefer to say for my team's benefit that we suck at estimating, rather than to say "we lied to the customers about exactly how well the current architecture matches their requirements" or "the partner lied to us about the exact depth of their business requirements."

Being charitable, I'd prefer to say that mistakes were made, without pointing the finger. We're all not perfect, and pretending that we can all be perfect all the time sets the wrong expectation, so I wouldn't try to pin it on a lie.

And I'd prefer to not have to see my boss going under the bus when I have to say "the reason we're not done on time, is because the boss told you this deadline and list of features was reasonable on that day without perfect information. If she had come to us and asked for our opinion, and given us time to talk it over, we would have worked it up and told you, it couldn't be done without making some concessions!"

If only for the reason that, perfect information is not usually available in the time allowed for making a decision. That's not just being charitable to the boss either, that's also self-preservation. The boss can take a lot more of those kind of hits than I can. Even more if we stay together on issues like this. And extending the time needed to make the decision also can have its own opportunity costs associated.

I agree with your sentiment in general. But not every bad datum that costs in accuracy, is the result of a lie. I've seen it said frequently that you should work to defer every decision until it's absolutely required, so you can make it with the best possible information and avoid those costs.

I think that's honestly a lot easier said than done.

I used to enjoy the medical TV series House with Hugh Laurie. The producers had as his dictum, "Everybody Lies" and his role as diagnostician was to work out who was lying, usually leading to a cure. A good manager is a good diagnostician for his or her organisation, able to take conflicting imperfect information and tease out the lies (or incorrect information)

A good leader is able to create a safe space where most people will release their defensive positions and many of the most intractable lies will fall apart.

But we all do lie, most often to ourselves, and not always with evil intent

But I fear the attitude that says "we expect you not to lie (withhold information, fail to speak out) because to do so will hurt the organisation, and you should have the best interests of the organisation / team at heart

Humans don't work like that.