FWIW, I think they should've been much more open in their announcement and credited original teams instead of selling this as some kind of almost-autonomous Claude project.

"We took existing system we helped to implement at Meta and changed it a bit" doesn't sound as cool as "Redesigning source control at Anthropic", but seems to be closer to truth?

Yes, they should have been clear that they ripped off an existing product instead of trying to make it sound like Claude came up with this amazing new thing.

I too can use LLMs to copy existing shit.

Yes, dishonesty. Flaunting this great technical achievement of their Mighty Labor Arbitrage Machine when it would have been impossible for them to have done without Mononoke already being open source.