The documentation says master: <a href="https://git-scm.com/docs/git-init#Documentation/git-init.txt---initial-branchltbranch-namegt" rel="nofollow">https://git-scm.com/docs/git-init#Documentation/git-init.txt...</a> but "may be subject to change"<p>When running "git init" on a fresh install, you also get a hint that the branch name may change. So I think they are still working on changing it to main upstream: <a href="https://lore.kernel.org/git/pull.762.git.1605221038.gitgitgadget@gmail.com/" rel="nofollow">https://lore.kernel.org/git/pull.762.git.1605221038.gitgitga...</a>
Not sure why it matters... Run "git config --global init.defaultBranch [whatever_name_you_want]" and then "git init".
The reason why "main" is used is to be more politically correct, so it is up to you.