Yes, really. Windows supports 'delayed rendering' (https://learn.microsoft.com/en-us/windows/win32/dataxchg/cli...), whereby an application can choose to not provide the data until requested. Thus, applications have a choice of either providing the data directly if it's a smaller amount, or delaying that if the amount is large enough that a performance impact can be expected.

Moreover, Windows will request that applications that are closing provide their previously advertized clipboard data, making the feature pretty much transparent to users. And some applications ask if you will still need your previous clipboard data when they close (Excel is one, I seem to remember).