No one in the Commonwealth seems to respect Sebastian, his mother included.
The self-absorbed narcissist has zero survival skills. We've seen him try and fail to try and kill walkers that are supposed to be target practice for him. When the walkers enter the Commonwealth, no one's risking their life to save this boy.
In the comics, Sebastian winds up shooting Rick Grimes dead and then rots in jail for his actions.
But I don't think this current version of Sebastian deserves to make it to the end. From the trailers, it looks like Sebastian is going to have a run-in with Negan, asking him if he knows who he is.
How does that happen? I have some thoughts.
Instead of killing Rick, the TV version of Sebastian may accidentally shoot his daughter Judith or someone else. That would explain Negan going after him in the trailer since he has a bond with Rick's daughter.
How we think Sebastian will die: If Negan doesn't kill him, walkers will do him in.