The developer has the LLM write the test suite, then the developer reviews those tests.

This pattern works really well.

"other than as a way to save some keystrokes which have to be understood anyway?"

It's exactly that. You can save so many keystrokes this way.

a test suite is a way to stochastically reduce certain classes of risk

it doesn't assert, or imply, correctness in the sense that is used here