They literally threw out every line of code that existed before and rewrote it in a completely different language, seemingly on a whim. That's how it was trashed, in the very literal sense that all of the existing project was tossed in the trash in favor of a completely brand new code base. That's a big deal even if you ignore the coding agent aspects.
The worst part is that they basically didn't review the new code at all other than making sure it passes tests. We have no idea what could be lurking in the codebase now, and it's even all completely un-idiomatic, Zig-ish Rust.
I swear they did this as a marketing ploy. To set the precedent that these large refactors are okay to do, and ingrain it in the engineering zeitgeist.
Kind of reminds me how Google starting putting on automatic AI processing of YouTube videos and shorts around the time of AI generated video and images. Their processing gave the videos artifacts that made them look more AI generated, making it harder to discern AI generated images, maybe to make demand for their watermark products.