5. The Avengers #2 Has Its First Member
Not the sequel, the second line-up. Marvel will have a problem on their hands when it gets to the end of Phase 3 and Infinity Wars Part 2 is released in 2019: some of their cast members will be pushing old age and aren't likely to be quite as sprightly as they once were. That would make the start of Phase 4 - which will now presumably open with Inhumans in July 2019 - the perfect opportunity to move the surviving members "upstairs". Tony Stark might still be there, but he's likely to be a monarch-like figure rather than a hero, but he's probably the only one - other than Hulk and Thor - who won't die before then (and Thor will likely just move home, while Hulk might not actually be on the planet anymore). The Avengers will be decimated, and someone (probably Stark) is going to have to assemble a brand new team. Could that mean the start of a New Avengers style initiative with Spider-Man, Wolverine and the characters introduced in Phase 3 (as well, perhaps as Luke Cage from his TV show)? If Spidey's cameo goes well, don't discount Marvel making a play to "borrow" him again for an more substantial role.