Some people dream death will be the next great adventure. Where we go and what we do is not something many human beings know much about. The desire to discuss it doesn't imply we should rush that transition. People of different belief systems have different ideas about how to commemorate the life of a deceased friend or loved one. Some people will celebrate and others will mourn the loss. Still others, would like no memory to be created in any shape or form.
One of the ways people can determine how well they know each other and themselves while alive is to ask people close to them to guess what they would like in an obituary, on an epitaph, in terms of a funeral or burial. These subjects aren't necessarily morbid, especially with the practicality of pre-paid funeral packages becoming increasingly popular in some countries. In fact, the nature and depth of discussion may reveal how much or how little you really know about someone. This realisation may prompt you to deepen relationships in the time you have.
It's interesting to notice the nature of feelings evoked inside you by the subject of such a discussion. Do you fear bringing the topic up at all? Might you think discussing it would invite death to happen prematurely? Other people assume the practical side and early preparation makes sense. Yet, how well do you think you know people you care about? Would your choices to commemorate their life be what these people really want? It may be good to discuss it early.