From , if the response of the message button contains update the prop "from_webhook": "true" will always be set. Which is not wanted if you e.g. use a bot account.
IMO this should just use the same logic as the other props: Copy it from the old post.
Conversation at: https://community.mattermost.com/core/pl/wbu5e9944ty1bc3cs5odbiud6y
in the description?