I think doctors are trying to give the patient and their family a sense of how much time they have left. If you are told you have only months to live, you will make very different plans from someone who is given decades to live. The shorter the prognosis, the more likely you’d try to rush to complete your bucket list!
About a month ago, my (Lesbian?) Aunt was given six months due to a stomach cancer diagnosis. She had been a nurse all her life and did not want extraordinary measures taken, so there was no attempt at surgery. She hasn’t been eating much, so she’s very weak. When we lived in Hawaii, she and her at-the-time roommate, Bonnie, took us to the drive-in theater to see all the ‘60s Disney movies in Auntie Bonnie’s VW Bug. She celebrated holidays and most of our birthdays with us when we were young. She was the closest to my mother of the five sisters.