Trello are an amazing team and an amazing product, and what makes the product so amazing is how domain-agnostic it is. They refuse at all costs to add any feature that helps use Trello in one specific way over others (e.g. lists = stages in task lifetime, cards = tasks; lists = assigned people, cards = tasks; lists = dates, cards = events, ...), and that made Trello equally useful as a Kanban board, a CRM, or for a beer microbrewery tracking its different barrels and the stages of brewing they are at. The best thing about Trello is when you start organizing your board one way, then organically drift towards a more natural way to organize them, sometimes without noticing as you do. Trello is for processes that you're not sure yet about the right way to manage.
Atlassian is all about development team collaboration. Trello can be used for that, but not anymore than it can be used for brewing beer. Trello shines when you don't know in advance how you will want to manage a project. If Trello became a dev collaboratin tool, I would stop using it for dev collaboration because there are better specialized solutions for that. Keep Trello general. Please.