I think they were describing the overall process, and how it’s ongoing. I sensed that the degradation comes from glitches that emerge when things get merged and go live. So, in other words, the code is more-optimized, but the changes need to be implemented better?
There are certainly a lot of newish performance issues that they’re still discovering following the latest update. They were just starting to figure them out, and it seems like it’s quite the tangle.