Thor: Ragnarok - Predicting Who Lives And Who Dies
2. Heimdall
Prediction: Dies
If the rumours about his eyes being the last Infinity Stone are true, then he's hardly going to function well when they're plucked out, but he might not even make it that far...
Why?
Much like Odin, Heimdall is probably too powerful to survive Hela's conquest of Asgard. He's the planet's guardian and an exceptionally strong one at that, and you'd have to think that for Hela to sit on the throne, she'd have to take out the most formidable line of defence.
It would make a lot of sense for Hela to kill off Heimdall and retrieve the Soul Stone - if it turns out to be true that his powers are owed to the stone - as it puts an Infinity Stone back on Asgard and gives Thanos a reason to go there (since the Tesseract will end up elsewhere with Loki).
Given the fact that Idris Elba has openly confessed his disdain for playing the character, it's unlikely he'd pass up an opportunity to kill him off.