You separated the group "engineers" into two new groups and then deleted the original group.

The problem that did not occur for Joe and John is that they could no longer view the billing history. This is because the billing history is not related to the groups or permissions in Jira, but to the organization and site administration. Only the organization admin or the billing contact can view the billing history for the products and subscriptions12

The other problems could have occurred for Joe and John if the group “engineers” had specific permissions or roles in Jira that were not granted to the new groups. For example, if the group “engineers” had the Browse Users global permission, they could select other users in dropdown fields, such as assignee or reporter. If the group “engineers” had the View Dashboard project permission, they could view some dashboards that were shared with the project. If the group “engineers” had the Edit Own Comments issue permission, they could edit their own comments on issues. If the group “engineers” had the Transition Issues issue permission, they could transition issues from one status to another345

References = View your billing history, Manage your bill for Standard and Premium plans, Manage global permissions, Manage project permissions, Manage project roles