To me this just illustrates that using tests meant for humans to test AIs produces questionable results.
Of course an AI is going to be able to produce a larger number of original ideas, it's designed to have much more data at its disposal than humans and be much better at using it, and correspondingly with access to more data it can produce more unique combinations from that data.
If anything, the fact that it's simply near the top of the pack rather than massively outstripping human minds, which are essentially hunks of wet meat with a slight electrical charge, demonstrates how far this technology has yet to go.
"I say your civilization, because as soon as we started thinking for you it really became our civilization, which is of course what this is all about."
-Agent Smith(The Wachowski Siblings) from The Matrix