Expect A "Distinctly Different' Marvel After 'Avengers: Infinity War'

What will the Marvel Cinematic Universe look like after Avengers: Infinity War? With many of Marvel's biggest stars nearing the end of their contracts, and Kevin Feige introducing a number of new heroes for Phase 3 and beyond, clearly there are a lot of changes in store.  But can we expect to see any of the characters we're familiar with stick around, Iron Man, Captain America, and Thor? Speaking with EW, Feige teased that some aspects of the first three phases will come to an end....

"I think you look at comics as a guide....I think there will be a finality to moments of Phase Three, as well as new beginnings that will mark a different, a very different, a distinctively different chapter in what will someday be a complete first saga made up of three phases."

He's playing coy, but clearly he's hinting at some characters going away for a while, possibly forever. Or maybe he's suggesting that different actors could be brought in to play familiar roles? Can anybody see someone else as Tony Stark at this point? That might be a tough sell. But maybe...what about Sebastian Stan or Anthony Mackie taking over as Captain America?