Prior to the official announcement of Yoshi's Crafted World's title, a fake leak was posted on 4chan listing off future Nintendo games, containing the title of Yoshi's Crafted World. This leak was humorous in nature, contrasting legitimate sounding titles such as Animal Crossing: Town Founder and Paper Mario: Clay Catastrophe with obvious jokes such as Metroid: Equestrian Races and Rhythm Heaven and Hell. This led to a short-lived theory that the leak was indeed real and slid in the joke names for humorous effect. Over time, reveals of installments in other franchises featured in the leak that didn't line up would show that Crafted World was simply a lucky guess. However, some other articles from the leak, such as a multi-part DLC pass for Mario Kart 8 Deluxe, Pokémon Diamond and Pearl remakes, a Tokyo 2020 Mario & Sonic Olympics game (albeit without Pac-Man), a Switch port of Overwatch, and the at-the-time-believed-to-be-cancelled Pikmin 4 would come into fruition later by coincidence.

During BlizzCon 2016, Mei's voice actress Yu Zhang revealed that the character's popular line "Sorry! Sorry, I'm Sorry. Sorry." was a botched take that was put into the game anyways. The following year, the game's senior designer at the time Michael Chu took credit for including the line in the game after catching the mistake on tape in the recording booth, citing it as his favorite voice line in the game.

Hanzo's character is likely inspired by the historical figure Hattori Hanzo, a famous ninja who served the Shogun during Japans Warring Period.

During development, Torbjorn had a mechanic where he had to develop his turret from a "stub" before it could shoot.

Hanzo's in May of 2014 development build used the third person animations from Reaper.

When the map Volskaya Industries was originally implemented, it had a capture point that also functioned as a payload.

Winston's leap originally had a targeting indicator in the form of a banana with a circle on it where he would land.

The payload was originally a truck during development. Its icon was the Doge meme.

Reinhardt's charge originally had no startup time. In some developer versions, he would run instead of charge with his armor's thruster.

Before his first person model was implemented, Zenyatta held Tracer's gun.

When Mercy was first implemented into development builds of the game, her healing ability was green.

In January of 2014 to , the game was playable to an extent. The only playable character was Tracer, health packs worked, Temple of Anubis was composed of Grey blocks, and capture points were functional.

The first playtest occurred in November of 2013 and only featured Tracer.

In April of 2014 during development, Reinhardt had the ability to throw his hammer.

In June of 2014, when Symmetra was first being tested, the model for Torbjorn's turrets was used as a placeholder for her turrets. The teleporter was functional at this stage.

When Hanamura was first implemented, Point B had a circular design, and the victory pose location on the map was the map origin as the victory pose placement tool hadn't been used yet. Since the origin was partially submerged, the development team referred to the victory pose screen as "The Hottub" as characters looked like they were in a bath.

In May of 2014, Hanzo was first implemented. His scatter arrow was first called Ricochet Shot, and Dragon Strike was labeled Spirit Dragon and was composed of orange spheres. The team called this iteration of Dragon Strike "The Caterpillar".

Widowmaker's ultimate originally put markers above characters' heads because the development team hadn't yet managed to get silhouettes to render through walls.

Early animation prototypes for Tracer had aggressive headbob which made headshots difficult.

During development, Reaper's model was used as a scale in order to determine building proportions.