Bitbucket for Slack includes historical commits on new branch push

Summary

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. 

t 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

Environment

Bitbucket Cloud + Slack

Steps to Reproduce

Push a commit to a branch, which contains only 1 commit

Expected Results

Get a notification about 2 commits in Slack

Actual Results

Getting a notification of 5 commits (2 from the branch + 3 from other branches)

Workaround

None yet