Could be simplified to just "teams.
These days from what I can see teams in organizations with no ability to devise a sane architecture usually take the microservice route. Management loves this new buzzword. To them it means problems go away.
After rearchitecting around services, pieces could be restarted and upgraded independently. As a customer, we didn't notice differences in the UI (e.g. the file storage on AWS).
Epilogue: They had a shared login system, multi tenant and all... which they recently replaced by a third party. Proof that services are replaceable, but also an acknowledgment that simple critical services can be hard at scale.
I personally believe that Atlassian switched to services at the right time, when it's hard to coordinate teams of thousands working on a dozen products, and when the monolithic approach was way past refactoring date ;)
Yes, they did that!
I don't understand how you engineer even a monolith like that in the first place.
I wouldn't look to Atlassian for anything regarding engineering practices.
Let's ammend this: so teams in large organizations +{that lack both a coherent architecture and the ability to devise one} can do independent releases +{by adoptiong the no-architecture architecture}.