I discovered that a reword option was added to --fixup back in git 2.32

The basic command looks like git commit --fixup=reword:<commit> and you can use it like you would the other autosquash commands.

I recommend creating an alias for it though. Thanks to this post, I’ve had a fixup alias that uses fzf to select form recent commits so I created a similar one for reword:

[alias]
  reword = "!git log -n 50 --pretty=format:'%h %s' --no-merges | fzf | cut -c -7 | xargs -o -I{} git commit --fixup=reword:{}"

Note, if you’re on Windows, you can install fzf via Chocolatey. And you might also be interested in PSFzf which a Powershell module that wraps fzf.