* Employees are adults who deserve to be treated with honesty, integrity, and respect. In a word: Trust. If they violate that trust, they're out.
I suspect if we indeed estimated a week's worth of work that ended up being literally a NO-OP, the kind of person I'd work with would realize this and re-assess the situation.
In the least, part of our process (and a "result" that people are tracked against) is "continuous improvement" and part of that would be recognizing we messed up somewhere to have that situation occur. Hiding this wouldn't be meeting that result.
It's an extreme example, agreed, but it illustrates a key point: if "management" can hold you accountable for not meeting your goals then they have to be comfortable when you do meet them. Part of the explicit agreement of ROWE is that this is a fair and equitable relationship. Having management assign you more work because you got it done "faster" goes against that agreement.
We track and iterate professional growth weekly. Thus, the expected results are set and evaluated on a week-by-week basis. People tend to find their unique rhythm within a few weeks and reach steady state.