Let's start from the business perspective.
It's well known that you'll only have an automated chaos if you'll automate a messy business process without any changes. So you need to invest some effort in the process redesign to get what you want from automation. It's million times easier with a BA since they are able to advise how to make your business process clear and efficient.
Moreover, it's so easy to forget about important things such as roles, permissions, reports, or to make your process insonsistent if you're not accompanied by an experienced BA.
When it comes to a development and then to a user acceptance test BA is here too - helping IT team to understand what the real business needs are and checking if all the requirements are met.
In a nutshell, we strongly believe that there is no automation without changing company's business processes so it's better to have not only an Atlassian administrator but also a BA in automation team