Spoilers for anyone who hasn't gotten up to chapter 967 in the manga
With regards to the iconic Roger Laughing panel when he gets to Laugh Tale, I think the reason Roger laughed when he got to Laugh Tale is because Joy Boy intended his treasure for someone who would live on and lead the world to a new future by overthrowing the World Government.
This would have been extremely ironic, since Roger was terminally ill and had just spent the final days of his life seeking a treasure that was meant for someone else, who would live long enough to be able to change the world.
I think that positions Luffy in a really interesting spot because he has been shedding his life span throughout the manga, like in Impel Down. It doesn't feel like a very Luffy thing to not take the one piece just because he doesn't have very long to live. I wonder if he would take whatever is on laugh tale and through sheer will power force the world to change before dying.