Given that Thanos needs the Mind Stone — yep, the same one in Vision's forehead — to complete the Infinity Gauntlet, it looks like the vibranium android's days are numbered, since the stone is what makes him the closest thing to a sentient being. In the first trailer, Thanos yanks the stone from his head, which isn't a great a sign for the android at all.
We've been seeing sparks fly between Scarlet Witch and Vision, so if his death should happen, it would further deepen Wanda's character journey and have serious implications for her in Avengers 4. We've already seen her grappling with her brother's death, as well as her guilt for the casualties that she caused in Lagos.
Through a stroke of luck, Shuri or Iron Man might be able to rebuild Vision if he dies, but we won't count our eggs before they hatch. In the trailer, we do see him take a human form as he shares a tender moment with Scarlet Witch. Still, it's important to note that, first of all, he still has the Mind Stone in his head, and second of all, this form could very well be part of a surreal dream sequence.
