The functionality is described at https://confluence.atlassian.com/display/BITBUCKET/Configure+Automatic+Team+Invites.

Issue: 'Developers' group is added to a newly created organization as default group and thus all newly created JIRA users are automatically invited to the group if the group exists on Bitbucket.

Expected solution: The group should be added for OnDemand instances and only for integrated accounts but not for BTF instances.

Workaround:

1. Go to DVCS Accounts page
2. Choose Configure automatic access for the corresponding organization
3. Uncheck the Developers group if present
4. Press Save button