Patients under general anesthesia don’t, sedation is less certain. For obvious reasons, there’s no corpus or research into the issue, so it’s left to supposition. Remember that “sedation” and “unconscious” are not necessarily the same.

The article addresses that.

>Whether palliative sedation truly ends suffering is not knowable, although doctors perceive indications that it does. “You might be able to tell if their blood pressure goes up. Same with their pulse,” said Nancy Crumpacker, a retired oncologist in Oregon. “And you read their faces. If they are still bothered somehow, it will show in their facial expression.”

Even under general anesthesia some patients feel the pain

https://en.wikipedia.org/wiki/Anesthesia_awareness#Backgroun...

That’s a matter of insufficient drugs being used, not a feature of the drugs themselves.