You can use whatever branch name you want. I think that it is probably not necessary or helpful to rename branches in existing repositories, but you can do tha

You can use whatever branch name you want. I think that it is probably not necessary or helpful to rename branches in existing repositories, but you can do that if it is helpful for what you are doing. If you upload a repository to GitHub, you can use whatever default branch name it already has with no problem. I know because I did upload one that uses "trunk" as the default branch name, and it did not cause any problem. (I used "trunk" as the default branch name because it is a mirror of a fossil repository which uses "trunk" as the default branch name.) (And, someone does get a minor benefit to call it "main"; it is two letters shorter than "master". Of course, that is minor, but it isn't quite nothing.)