Blizzard recently showed a photo at BlizzCon of many concept heroes that Overwatch (TM) was considering adding. One of which was a character named "Mama Hong". Immediately Overwatch fans erupted in excitement and she has the largest fanbase out of all the heroes in the original concepts photo. 

Not only does she have a large backing now, but she would also offer some more diversity to the Overwatch lineup. As body image is a problem that many of the worlds youth face, introducing a powerful woman who is also overweight could allow some fans to have better body image. 

In conclusion Mama Hong should be the next Doomfist, a character not originally included but by popular demand added.