I think it's called "changeset" at Google, or at least was, and "PR" is becoming pretty common everywhere because of GitHub. But "diff" seems to be gaining some ground as a general term in the monorepo/unified-build/trunk-only world. Uber uses/used Phabricator and I think there are some other high-profile shops as well.
I don't know that there's like one leading term, but I think everyone knows what "diff" means both literally and as a connotation that it's a rebase rather than merge workflow.
I don't know that there's like one leading term, but I think everyone knows what "diff" means both literally and as a connotation that it's a rebase rather than merge workflow.