That argument lands you in the “we can’t know which religion is true” category, because if we can’t know the plans of god, we also can’t know which god is real.

So, while it absolves the believer from having to answer the problem of evil, it simultaneously robs them of any certainty about the truth of their religion.

But only if they think about it.

It’s also very often used as an argument against rehabilitation in prisons:

If free will exists, then crime is a choice. If you choose crime, you are a bad person, and punishment is the only way forward.

If you commit the crime again, it’s because the punishment didn’t work, and/or because the person is simply bad, so a longer punishment is needed, and infinitum.

It’s also used to justify the death penalty, which would not make any sense in a deterministic universe.