Not that complicated, really. I'm part of Picnic now for quite a while. That's the 'we'. Of course I've discussed the origin story as used in the post at length with my close colleagues who were there from the beginning. Also, I'm very much part of the current choice not to migrate to e.g. Kotlin based on such discussions. So yes, this is our story which we want to share widely. It comes up every now and then, so now we have something to point people to. Didn't expect this to get picked up by HN, though!
The article unquestionably leaves the impression that you were there when the choice was made.