NOTE: This article contains SPOILERS for Guardians of the Galaxy Vol. 2.
One of the five post-credits scenes featured in Guardians of the Galaxy Vol. 2 does not set up a future plot point for Avengers: Infinity War, despite fans' hopes. Ever since Samuel L. Jackson's Nick Fury showed up to talk to Robert Downey Jr.'s Iron Man about the burgeoning Avengers Initiative, the post-credits - and eventually mid-credits - scene has played a vital role in wrapping up each MCU film. Some of them are just there to put one last laugh on the end for fans, while others provide vital clues to or outright set-up the plot of future MCU installments.
This past weekend saw the latest MCU blockbuster - James Gunn's Guardians of the Galaxy Vol. 2 - continue the studio's winning streak at the box office, already topping the $400 million mark worldwide after only a few days in theaters. Guardians 2 was certainly no slouch when it came to tag scenes presented after the film proper, offering up no less than 5 extra scenes either during or after the credits.
In arguably the most notable of these credits scenes, Sovereign leader Ayesha is seen introducing Adam, a new artificial being that she has created to further her plans for revenge against the Guardians. This scene seems to be pretty clearly setting up the arrival of Adam Warlock, a powerful character whose Marvel Comics lineage dates back to the 1960s. With the Guardians' next MCU appearance slated for 2018's Avengers: Infinity War, many fans assumed that this was pointing toward Adam making his debut in that film. However, during a recent interview with /Film, Marvel Studios boss Kevin Feige unequivocally refuted that assumption:
Is something like that conceived as just like “Oh, it’s a fun thing and oh maybe if it gets played in another movie of Adam Warlock?” Or like are you consciously thinking of oh, we need Adam Warlock down the line, Infinity War, whatever, let’s…
Adam is not in Infinity War. That is not a tag for Infinity War.
But it varies. It varies. In that case in particular, James has ideas. And had played with incarnations of Adam Warlock in earlier drafts of other Guardians films. So he’s always been top of mind for the Guardians franchise. And if he appears anywhere in the future, it’ll be with Guardians.
So, there one has it, Adam Warlock is not a part of Infinity War. Also, based on Feige's second statement above, Adam will not be injected full-on as a character in the MCU within any other sub-franchise than Guardians. With the MCU schedule already filled in through 2019, that means he won't be seen on-screen again until at least 2020.
With writer/director Gunn already hard at work developing the as yet undated Guardians 3, this likely points toward Adam Warlock and Ayesha playing a role in that movie, unless of course Gunn is planning way, way ahead. Considering the smash success of Vol. 2 though, it wouldn't be entirely unthinkable to imagine that visions of a Guardians 4 are already dancing through Gunn's mind.