Idk why people are worried about Luke dying in future movies. If they kill Luke in TLJ (or later), they’ll surely Force Ghost him and he’ll still be there, just bluer and less opaque.
I’m sure for some it would be nice to see Luke Skywalker: Jedi Knight.
For me, the Star Wars universe has become so much more than Luke Skywalker, Han Solo and Darth Vader so as long as the story is good I’m ok with whatever they decide. I think.