The github change is brought up by a lot by people, but, all github does here is this. On the default set of commands it shows you if you don't have a repo pushed, it shows you the help command with 'main', instead of 'master'. Just a word change on a default help document, that's it. If you knew your commands you wouldn't even notice this.
If you just make a repo and push your existing code to github, it will work with 'master' as it is.. they actually don't have much of a say in how people name the git branches without severely shooting their whole service in the foot..
iirc git was also looking in to changing the default name when you run git init. Yes, it makes no difference at all, its just a name. But the fact is that a lot of people felt it very important to make this nonsensical change. There is no reason why the colors of chess pieces would not fall under the same justifications.
It was GitHub who wanted to make this change. I don't think they can impact how the git command works. GitHub has a separate desktop UI client but afaik the git binary is from a different organization.
I think if you look at arbitrary religious restrictions, those also probably trace their origins to an overactive neurotic mind with too much time on their hands. Those guys then develop nonsensical restrictions.
If you just make a repo and push your existing code to github, it will work with 'master' as it is.. they actually don't have much of a say in how people name the git branches without severely shooting their whole service in the foot..