Avengers 4: 8 Spoilerific Predictions For The Real Title
4. The Death Of The Avengers
The Spoiler: Everyone dies.
This might be the MCU and Kevin Feige might have said that there will be no sudden turn to darkness, but he can't continue to expand the series' cast without getting rid of some of the veterans. Through the natural attrition of contracts ending, ageing out of roles and lessened interest, it's getting to the point where the actors who built Phase 1-3 should start to be moved on.
Feige has said that he plans to recast at that point. but it would still be better to do that in a sort of Doctor Who regeneration style, rather than just replacing them James Bond style. So, why not have Infinity War end on an almighty downer, with Thanos clicking his Gauntleted fingers and killing half the Avengers? The older half obviously.
It doesn't need to be permanent obviously (what is in comics?), but then leading to Nebula (or someone else) reversing the effects, and having the dead replaced by new actors would be a very smart move. Unless they want to be REALLY brave and just not replace them at all?