Bitbucket for Slack includes historical commits on new branch push

When a new branch is created in Bitbucket and the Slack channel has subscribed to the commits_pushed webhook a message will display in Slack which always contains the top 5 commits on the branch whether or not they are new to the repo. It would be ideal if only new commits were displayed when a new branch is pushed.  Raised from the community here: https://community.atlassian.com/t5/Bitbucket-questions/New-branch-notifications-in-Bitbucket-Cloud-for-Slack-have-too/qaq-p/1065630

See also: https://confluence.atlassian.com/bitbucket/event-payloads-740262817.html#EventPayloads-Push