The Infinity War trailer that debuted at D23 and San Diego Comic-Con portrayed Josh Brolin’s Thanos as a pure world-destroyer (literally, he uses the Infinity Gauntlet to destroy a planet or moon and bring it hurtling down on The Avengers), and it appears that these heroes will be in more danger than we have seen them in before.
Fans have speculated about who will die before the end of Phase 3, and it still seems incredibly likely that some of these casualties will take place in Infinity War.
The possibility of someone going down in a blaze of glory before Avengers 4 seems even more likely when we consider the sheer scale of the footage already released to a select group of fans.