They named the character after an employee they recently had to fire, presumably for sexual harassment.
Blizzard is currently involved in a massive lawsuit after a 2 year investigation that showed that they allowed women to be harassed and mistreated. There is even suicide involved.
The real Jesse McCree was seen taking part in a group called the Cosby Suite, where one of the biggest abusers named in the suit would harass women. McCree was part of that group and praising the harasser. He has since been let go. He did not work for the Overwatch team. The character was named after him and he gave his permission for the name, but it was not named to honor him.
Some of the female developers have wanted things to be changed in-game in addition to sweeping reform to how they handle harassment and pay disparities in the workplace.
This name change is part of that.
- They said they will be working with the content teams in non-English areas to ensure the new name is appropriate.