> It would help especially when the commit message was written badly.
>
> Or it might be possible to customize just like "git log --format"?
It is possible to change the format globally via config option
rebase.instructionFormat:
$ git config rebase.instructionFormat "%an (%ad): %s"
The format is the same as for 'git log'. This one outputs author
name, date, and the first line of commit message.
This option is supported since Git 2.6.
Or are you interested in a command-line option that can change
the format on per-invocation basis? I think there isn't one.
It can be interesting to add it, but I don't think it has much
utility...