The latter. When "understand", "reason", "think", "feel", "believe", and any of a long list of similar words are in any title, it immediately makes me think the author already drank the kool aid.
kool aid or not -- "reasoning" is already part of the LLM verbiage (e.g `reasoning` models having `reasoningBudget`).
The meaning might not be 1:1 to human reasoning, but when the LLM shows its "reasoning" it does look _appear_ like a train of thought. If I had to give what it's doing a name (like I'm naming a function), I'd be hard pressed to not go with something like `reason`/`think`.