Nitpick, but GitHub pull requests (which are
really merge requests, you aren't pulling anything) are named after the actual pull requests used eg. between kernel maintainers. ("Please, could you pull from ...")
I guess it might be more accurate for me to think about pull requests as Github's reification of the social protocol of pulling among kernel developers.
Git has tooling to help with those, so it kinda is a git feature: git request-pull. https://git-scm.com/docs/git-request-pull