Assuming you were the one who amended the commit before pushing it up to the remote, there's no reason that you would not be able to delete the branch because your local working copy has already updated contents of .git/refs/heads/my-feature-branch.
For those who have cloned the repo for testing, they can simply run git checkout my-feature-branch; git fetch origin; git reset --hard @{u} to get their local repo in sync with the remote.
So there's no reason that amending the commit will affect anyone until they branch off of the repo to do their own work. But that's nothing that a rebase can't fix.
Yes, of course there are workarounds; no matter what scenario you or I come up with, the other will be able to propose a different way of doing things. I chose a deliberately trivial example because I was illustrating a fundamental aspect of Git's design, not trying to stump you. But we're talking past each other.
But one of my comments (†) is the great-grandparent of your first comment on the subthread? (∆) And the concept of preserving commits precisely is fundamental to my comment two generations above that, the one about "nirvana" (‡) ?
Perhaps we would benefit from an `hn log` function which displays the linear parentage history for comments? (It would be easier to design that `git log` because every comment has exactly one parent, there are no `hn merge` comments.)
Or in your working copy has my authorship info been lost? That can happen if a committer uses plain old `patch -p1` to apply a diff from the mailing list rather than `hn am`. :D
> Or in your working copy has my authorship info been lost?
Well, none of the text that you originally wrote in the comment you're referencing wasn't preserved on the working copy. And, unless it's quoted, and one could search for when it was introduced by running git log -S"a line from your comment", no one is going to search for it specifically. IOW, the thread moved on :).
For those who have cloned the repo for testing, they can simply run git checkout my-feature-branch; git fetch origin; git reset --hard @{u} to get their local repo in sync with the remote.
So there's no reason that amending the commit will affect anyone until they branch off of the repo to do their own work. But that's nothing that a rebase can't fix.