Sort of, yeah. When GP says "it's almost impossible to measure", that does not mean that upper management does not in fact have some sort of metric that says "productivity" on the label. But what they're measuring is most likely going to have a tenuous relation to actual productivity.

A common problem is that they’ve noticed something real but are misattributing the cause. Sales are down - is it because the salespeople are slacking or because the mid-pandemic buying spike wasn’t the new normal? A big project is behind schedule - is that because people are working from home or because you have some senior managers playing politics?

In this case, the commercial real estate industry has been making a huge PR push trying to keep the value of their portfolios up so senior managers at most companies are regularly hearing that WFH causes problems - and anyone distrustful and/or looking for an excuse to shift blame is likely to seize on it.