nutrition at end of life

Death of dehydration or hunger is unrelated to the dying process, and is considered as unacceptable hastening of death. Therefore, halachically food and fluid must be provided to any person, including a terminal patient. There is a dispute between R. Feinstein and R. Auerbach if food and fluid has to be provided even by force to a competent dying patient. However, if the patient is comatose or otherwise incompetent all agree that food and fluid should be provided by all means (even depite a living will), including NG tube or PEG unless medically (not philosophically) contraindicated.

In summery:

Feeding by NG tube or PEG is obligatory in all patients unless they are expected to die from their disease before they will die of starvation. Therefore with your question, it depends on how terminal the patient was judged to be.