Thomas, typically, is further along the same trajectory. Although there are references to violent death (e.g. Logion 98), the references to natural death are now more common than they were in the Synoptics, as in these sayings (Lambdin's translation):
59: Jesus said, "Take heed of the living one while you are alive, lest you die and seek to see him and be unable to do so."Logion 59 occurs in a cluster of material in which life and death is a key thread, from logia 58-61 and again in 63. Logion 109 shows us that as in Luke, natural death is now a feature of the parable material. Indeed Thomas's parallel to the Rich Fool (Luke 12.15-21 // Thomas 63) ends with the narration of the man's death ("that same night he died") rather than the death being implied in God's address, as in Luke.
109: Jesus said, "The kingdom is like a man who had a hidden treasure in his field without knowing it. And after he died, he left it to his son. The son did not know (about the treasure). He inherited the field and sold it. And the one who bought it went ploughing and found the treasure. He began to lend money at interest to whomever he wished."
Perhaps the clearest example of the same phenomenon occurs in Thomas's version of a the double tradition saying Matt. 24.40-1 // Luke 17.34-5. Luke's version of the Matthean saying is closest to Thomas's but both Matthew and Luke speak of people being "taken" rather than dying:
Luke 17.34-5: "I tell you, in that night there will be two in one bed. One will be taken and the other left. There will be two women grinding together. One will be taken and the other left."Thomas 61: Jesus said, "Two will rest on a bed: the one will die, and the other will live."
Thomas, even more than Luke, comes from a time where natural deaths have found their way into the representation of Jesus' teaching. It's one small sign among several others that Thomas belongs to a slightly later historical context.