Depends. If the ending is an "inflection" point just like Marineford, then I can see Oda doing fucked up shit again like he did with Ace/Whitebeard.
Luffy does seem pretty 50/50 depending on how hard his final battles could be and him becoming a "legend" in the world (i.e. greater than Roger or Joyboy). Usopp less so, but he does talk about being a great man even if he were to die.
Luffy constantly makes allusions to him dying at the cost of achieving great things. As does Zoro.
Could they all die by the end? No idea, but I think Marineford shows us that anything can happen, especially in the EoS.
Luffy does seem pretty 50/50 depending on how hard his final battles could be and him becoming a "legend" in the world (i.e. greater than Roger or Joyboy). Usopp less so, but he does talk about being a great man even if he were to die.
![](https://64.media.tumblr.com/fe9f1835c735b48293ebefb92d53ab4d/tumblr_inline_oup3kh0f0d1sg3o5d_540.png)
Luffy constantly makes allusions to him dying at the cost of achieving great things. As does Zoro.
Could they all die by the end? No idea, but I think Marineford shows us that anything can happen, especially in the EoS.