I'd guess at Abraham, or Glenn.
Abraham, as he avoided the character's intended fate when Denise switched in and took an arrow for him. He also made a few comments about his future with Sasha, wanting children etc. which is never a good omen. Also stood up to Negan.
Glenn, if they're staying true to the comics. The POV shots from inside the van throughout may have been through the eyes of the same person as at the end, as the article posted above suggests, and that'd mean that it's one of the 4 who were in the van. Glenn would be the obvious candidate.