Many people want to know the progress of your return while in process. That is why the refund amount is there.
The feedback from the person doing the returns wanted this feature.
Once all the income is entered, then it starts to make more sense, as you add a deduction you may be able to see the tax impact on the refund (if any).
You are correct, it that in the early stages of doing the return, this refund number can be misleading until all the income is entered.