Could you give an example of people who explicitly claim that sentience is equivalent to intelligence? I’d agree that some arguments trade on an equivocation between the two, but I don’t think their adherents intentionally do so.
The post I replied to seemed to make the conflation. Because “just guessing the next word” seems like a reasonable refutation to sentience, but not to intelligence.
I agree that it’s not usually an intentional mixup. From what I’ve seen it’s mostly a lack of rigor in defining terms.