Dementia pt had aspiration, back on o2, to be bed bound, very robust appetite now plummeted, has hospice care of some kind. What does this portend?

Ask the Dr. From your description, it does sound like the pt is not expected to live very long - but that may reverse in many. Still, this is an ill individual who will require some level of supportive care in all likelihood. No one can predict w/ certainty - so plan for the worst and hope for the best.