With the much-anticipated release of Avenger: Endgame, Marvel will prove one fundamental concept—they are indeed the master of freewheeling when it comes to connecting the dots. As reality would have it, the original plan for its shared universe of characters was intended to culminate with a very different version of the Avengers than fans ended up getting.
Although now it may feel very much like from the very first Iron Man that the road was always leading to that of Thanos. However, it would seem that in truth that was not always the true plan. The Avenger’s mid-credits scene that featured the mad Titan known as Thanos was a last-minute inclusion and decision that was made by the great one himself—Joss Whedon. Admittedly by adding the scene, Whedon had no idea to what end it would lead, as the story involving Thanos wasn’t really brought to fruition until many years later.
However, through the popping up of random aspects through the MCU, such as Loki’s scepter sporting the Mind Stone, to the Tesseract actually being the Space Stone, to the Infinity Gauntlet being spied as an “easter egg” in Odin’s vault—all needing in fact to be retconned to connect the eventual dots.
To get to where they are now, Marvel and Kevin Feige had to have developed a multitude of variations of the Avengers Initiative. Keep in mind, the end game of Phase 1 is and always was intended to be that of the Avengers.
In fact, all of the initial funding that started in 2005 for Marvel Studios, and then to be made Iron Man, was predicated on the fact that Avengers would be made—a means to an end as it were. What wasn’t known at the time was the exact version of that Avengers team would actually come to pass.
From the first tease of Fury offering Stark a proper place in the Avengers initiative to the years later tease of Thanos create by Whedon, there was a plan. Albeit a continually shifting and morphing plan, but a plan none the less. And so, now, in a few days, that plan will come to flourishen, and Phase Three will complete an arc that was literally decades in the making.