There is little doubt that Thor's brief exchange with Thanos in the Battle of Wakanda was an important moment in Avengers: Infinity War. However, the film's new art book reveals that things may have gone differently.
In Infinity War, Thanos has just procured the Mind Stone from Vision when Thor attacked him with the new axe, which he drove into the Mad Titan's chest. The art book confirms that the Odinson was meant to miss the head in the original concept art. However, it looks like Thor was supposed to get some help from his friends. Take a look at the photo below (via ComicBook.com).
The final confrontation certainly looks like the epic fight on Titan where the Guardians of the Galaxy teamed up with Iron Man, Doctor Strange, and Spider-Man to remove the Gauntlet. However, the concept art makes use of Hulk, Black Widow, and Captain America holding on to Thanos as Thor moves in with his axe. Interestingly, it looks like the Hulk isn't pleased with the Odinson burying Stormbreaker into Thanos' chest.
It's possible that the concept art depicts an early plan for the film but the scene was utilized for the awesome Titan sequence. Either way, it still looks like Thanos wins because Thor missed the head.
Thor's decision to aim for the chest was a great frustration for fans. However, it made sense since he wanted the Mad Titan to witness defeat and avenge his brother Loki. Additionally, that would mean they would be facing a completely new villain in Avengers 4.
Thor will return in Avengers 4, which premieres on May 3, 2019.